JPH045458A - Internal combustion engine control device - Google Patents

Abstract

PURPOSE:To perform cylinder control even at the time of high speed rotation by using a third standard position having the largest spark advance as the control standard for high-speed rotation time, and a fourth standard position delayed from a first standard position as the electrification start timing for bypass ignition time. CONSTITUTION:When a rotary disk 2 is rotated in the arrowed direction, on the basis of windows 3a1 and 3a2, a third standard position B 110 deg. and a first standard position B 75 deg. are obtained by the first pulse P1 of crank angle standard signal L1, a fourth standard position B 40 deg. and a second standard position B 5 deg. by the second pulse P2. The cylinder identification signal L2 based on a window 3b is generated with a phase shift to the first pulse P1 of a specified cylinder. A microcomputer identifies the specified cylinder on the basis of the cylinder identification signal L2, and takes the first standard position B 75 deg. as a control standard for ignition timing at the time of general rotation, and the third standard position B 110 deg. as the control standard at the time of high speed rotation. At the time of initial ignition in the initial stage of start, as the microcomputer can not function, bypass ignition control is performed according to the second pulse P2.

Description

Detailed Description of the Invention [Field of Industrial Application] The present invention relates to an internal combustion engine control device that controls each cylinder based on a plurality of crank angle reference signals from a rotation signal generator. The present invention relates to an internal combustion engine control device that achieves power savings during control and bypass ignition.

[Prior Art] In general, internal combustion engines applied to automobiles etc. have a plurality of cylinders (for example, 4 cylinders) with a speed of several 1100 rpm to several 1000 rpm.
It is driven to rotate at about rpm. In the case of 4 cylinders,
Each cylinder is connected to the drive shaft (crankshaft) so that its operating position is out of phase by 1/2 cycle. Also, in the case of a 4-stroke engine, for 2 revolutions of the crankshaft,
Since the four cycles of intake, compression, explosion, and exhaust are performed, the camshaft that controls the drive cycle of each cylinder is
The cylinders are connected so that their operating positions are out of phase by 1/4 period.

In such internal combustion engines, in order to electronically control the ignition timing by the igniter and the fuel injection timing by the injector for each cylinder, a crank angle reference signal is generated for each cylinder in synchronization with the rotation of the internal combustion engine. However, it is necessary to identify the operating position of each cylinder based on this crank angle reference signal. Usually, a rotation signal generator that detects the rotation of a camshaft or crankshaft of an internal combustion engine is used as a means for generating a crank angle reference signal corresponding to the reference position of each cylinder.

Figure 4 is a block diagram showing a general internal combustion engine control device. In the figure, (8) is a rotation signal generator that generates a position signal corresponding to each cylinder, and (9) is a rotation signal generator that takes in the position signal. This is an interface circuit for The position signal is a cylinder identification signal and a crank angle reference signal (described later).
Contains.

(10) is a microcomputer that takes in the crank angle reference signal via the interface circuit (9), processes the position signal to identify the operating position of each cylinder, and uses timer time control from a predetermined reference position. , energization, fuel injection, ignition timing, etc.

FIG. 5 is a perspective view showing a specific configuration example of a rotation signal generator (8) used in a conventional internal combustion engine control device.
The figure is a circuit diagram showing a position signal generator provided in the rotation signal generator (8).

In FIG. 5, (1) is a rotating shaft that rotates in synchronization with the internal combustion engine; for example, a camshaft that rotates once in synchronization with one period of the four-cycle operation of the internal combustion engine (or one cylinder consisting of it). is connected to.

(2) is a rotating disk attached to the rotating shaft (1), and corresponds to the reference position (predetermined crank angle) for each cylinder.
Further, a plurality of slit-shaped windows (3a) and (3b) are provided corresponding to the reference position of the specific cylinder.

This example shows the case of an internal combustion engine with four cylinders, and windows (3a) corresponding to the crank angle reference signal for each cylinder are provided at four locations on the outer periphery. Further, the front end of each window (3a) in the rotation direction (arrow) corresponds to the first reference position for each cylinder, and the rear end corresponds to the second reference position.

On the other hand, the window (3b) corresponding to the cylinder identification signal is provided at one location on the inner circumference corresponding to the window (3a) for only a specific cylinder (first cylinder), and is provided in the rotation direction with respect to the window (3a). It has a phase difference.

(4a) and (4b) are a pair of light emitting diodes arranged to face each window (3a) and (3b), respectively, and (5a) and (5b) are from each light emitting diode (4a) and (4b). A pair of photodiodes arranged to receive the output light through windows (3a) and (3b).

These light emitting diodes (4a) and (4b) and photodiodes (5a) and (5b) constitute two sets of photocouplers.

In FIG. 6, light emitting diodes (4a) and (4b)
The photodiodes (5a) and (5b) are typically shown as (4) and (5), and only one photocoupler is shown. (6) is an amplifier circuit that amplifies the output signal from photodiode (5), <7)
is an oven collector (grounded emitter) output transistor whose base is connected to the output terminal of the amplifier circuit (6). The collector terminal of the output transistor (7) is connected to an interface circuit (9) (see FIG. 4).

Next, while referring to the waveform diagram in Figure 7,
The operation of the conventional internal combustion engine control device shown in the figure will be explained.

When the rotating shaft (1) and the rotating disk (2) rotate in synchronization with the internal combustion engine, the windows (5a) and (5b) arranged opposite to the windows (3a) and (3b) emit light from the windows. (
Corresponding to each of 3a) and (3b), two types of pulse signals are output, rising at the front end and falling at the rear end. This pulse signal becomes a position signal via an amplification circuit H (6) and a transistor (7), and is passed through an interface circuit (9) to a microcomputer (1).
0).

As shown in FIG. 7, the position signal includes a crank angle reference signal L1 called SGT and a cylinder identification signal L2 called SGC.

Among these, the crank angle reference signal L1 obtained based on the window (3a) is set to the first reference position (B75°) and the second reference position 1! for each cylinder #1 to #4. This results in a plurality of pulse trains that are inverted at (B5°).

The rise of each pulse (B75°) is the TD of each cylinder.
It indicates the position 75° before C<crank angle 0°=top dead center), and serves as the control reference for cylinder operation during normal running. Further, the falling edge (B5°) indicates a position 5° before TDC, and serves as a bypass ignition timing at startup when the microcomputer (10) cannot operate.

On the other hand, the cylinder identification signal L2 obtained based on the window (3b)
is a pulse corresponding only to the crank angle reference signal L1 of a specific cylinder, that is, #1 cylinder, and is used to identify the specific cylinder. The cylinder identification signal L2 has a different phase from the crank angle reference signal L2, and in this case, it rises before the rising edge (B75°) of the crank angle reference signal L2 and falls after the falling edge (B5°) of the crank angle reference signal L2.

The operating position of each cylinder identified by the crank angle reference signal L1 is shifted by 1/4 period with respect to one period of the camshaft (corresponding to two periods of the crankshaft, that is, 720°), and 1/2 period (180°
) are shifted by Also, as is well known, each cylinder is #1
The cylinders operate in the order of cylinder #3, cylinder #4, and cylinder #2.

Based on the crank angle reference signal L1 and cylinder identification signal L2 thus obtained, the microcomputer (10) identifies the specific cylinder and the operating position of each cylinder, and determines the energization start timing, ignition timing, fuel injection, etc. Performs calculations and control. For example, the first reference position B75° is used as a reference, and the control is performed such that energization is started after a predetermined time has elapsed, and ignition is started after a predetermined time has elapsed.

At this time, as the rotational speed of the internal combustion engine increases, the time to reach the target operating position is shortened, so the control reference position is set to B75.
It is desirable to advance the angle by more than °.

However, in order to advance the first reference position fi B 75°, it is necessary to form a long window (3a) on the rotating disk (2), which deteriorates the strength of the rotating disk (2). Put it away. In addition, during bypass ignition, the first reference position 7B 75° is the energization start time and the second reference position B5° is the ignition timing, or if the energization time becomes longer due to the advance of the first reference position, This is not practical as it increases power consumption and causes problems such as heat generation.

[Problems to be Solved by the Invention] Conventional internal combustion engine control devices generate only one crank angle reference signal and pulse for each cylinder. It will be done.

Furthermore, in order to cope with high-speed rotation, the first reference position, which is a control reference, must be set to a certain degree of advance, so that the energization time during bypass ignition becomes longer.

Therefore, power consumption during bypass ignition increases and generates heat.
There were problems such as the need for a heat sink to prevent heat generation and destruction. Also, when the rotation speed increases during normal cylinder control, the control reference is changed to the first reference position fiB75.
Since the angle cannot be advanced from a degree, there is a problem that it cannot be applied to high-speed rotation.

This invention was made to solve the above problems, and the number of pulses of the crank angle reference signal is set to two for the ignition cycle of one cylinder, thereby shortening the energization time during bypass ignition. Another object of the present invention is to provide an internal combustion engine control device that advances a control reference position in accordance with the rotational speed and enables control during high-speed rotation.

"Means for Solving the Problems" In the internal combustion engine control device according to the present invention, the crank angle reference signal is set at a third reference position that is more advanced than the first reference position with respect to the ignition cycle of each cylinder. It has a first pulse that is inverted and a second pulse that is inverted at a fourth reference position that is retarded from the first reference position and advanced from the second reference position, and corresponds to each cylinder. It has two pulses.

[Operation] In this invention, the third reference position with the largest advance angle is used as the control reference during high-speed rotation, and the fourth reference position, which is retarded from the first reference position, is used as the energization start timing during bypass ignition. shall be. This allows cylinder control even during high-speed rotation, and reduces energization time even during bypass ignition.

[Example] Hereinafter, an example of the present invention will be described with reference to the drawings. 1st
The figure is a perspective view showing a rotation signal generator used in one embodiment of the present invention, (1), (2), (3b), (4a).
), (4b), (5a) and (5b) are the same as in FIG. Further, the overall configuration of one embodiment of the present invention is as described in the fourth embodiment.
As shown in the figure.

(3al) and (3a2) are windows for generating the crank angle reference signal L1, and the preceding window (3a,) with respect to the rotational direction of the rotating disk (2) is the window for generating the crank angle reference signal L1.
1 (described below) and the trailing window (
3a2) corresponds to the second pulse. In this case, the configuration of the rotation signal generator (8) includes a pair of windows (
The structure is the same as shown in FIGS. 5 and 6 except that 3a, ) and 3a2 are formed, respectively.

Next, the operation of an embodiment of the present invention will be described with reference to the waveform diagrams of FIGS. 1 and 4 and FIGS. 2 and 3.

Similarly to the above, when the rotating disk (2) rotates in the direction of the arrow,
Based on the windows (3a1) and (3a2), a crank angle reference signal L1 consisting of a pulse train is obtained as shown in FIG. This crank angle reference signal L1 has a first pulse P1 and a second pulse P2 corresponding to each ignition cycle of each cylinder, and has a total number of pulses twice as many as the number of cylinders.

At this time, the first pulse P1 due to the window (3a,
f1B110” and moves to the first reference position B75°
and stand down. Also, the second pulse P due to the window (3a2)
2 rises at a fourth reference position B40°, which is retarded from the first reference position B75° and advanced from the second reference position B5°, and falls at the second reference position B5°.

On the other hand, the cylinder identification signal L2 based on the window (3b) is generated so as to be out of phase with the first pulse P1 of the specific cylinder. That is, it rises on the advance side from the third reference position l B 110', falls on the retard side from the first reference position B75°, and on the advance side from the fourth reference position B40°. In this case, since the length of the window (3b) only needs to correspond to the window (3a,), it is formed shorter than the conventional example shown in FIG.

The microcomputer (10) identifies a specific cylinder based on the cylinder identification signal L2 and at the same time generates a first pulse P.
, can be identified. Therefore, based on the crank angle reference signal L1, there are four reference positions B110 for each cylinder.
degree, B75°, B40' and B5°, and the respective operation timings can be controlled.

For example, during normal rotation, the first reference position B75° is used as the control reference for ignition timing, etc., and during high-speed rotation, the third reference position BIIO'' is used as the control reference. However, it is possible to obtain a standard for timing control on the advance side compared to the conventional method, and it is possible to perform sufficient advance control such as energization start and ignition.Therefore, it is not affected by the maximum control position of the internal combustion engine, and is within the practical control range. Since the reference position 1 can be set, control is stabilized.

Also, at the time of initial ignition at the initial stage of startup, the microcomputer (10) cannot function due to a drop in battery voltage due to starter operation, so the second pulse P2
Bypass ignition control is performed accordingly.

That is, as shown in FIG. 3, energization is started at the fourth reference position B40°, and ignition is started at the second reference position B5°. As a result, the pulse duty at the time of bypass ignition is reduced, and the current flowing through the ignition coil is suppressed compared to the conventional case (-dotted chain line). Therefore, the thermal load on the electric power system is reduced, damage caused by heat generation is prevented, and there is no need to install a heat sink.

At this time, the width of the crank angle corresponding to the energization period is B40.
Even if it is shortened to B5°, the crankshaft rotates at a low speed in the initial stage of startup, so the energization time is long enough to allow ignition.

In the above embodiment, the first to fourth reference positions are set to B110', B75°, B40', and B5°, respectively, but it goes without saying that they can be set to any crank angle as necessary. .

[Effects of the Invention] As described above, according to the present invention, the crank angle reference signal is inverted at the third reference position on the advance side than the first reference position with respect to the ignition cycle of each cylinder. and a second pulse that is inverted at a fourth reference position that is retarded than the first reference position and advanced than the second reference position, and has the largest advance angle. The position is used as a control reference during high-speed rotation, and the fourth reference position, which is retarded from the first reference position, is used as the energization start time during bypass ignition, so that cylinder control during high-speed rotation is possible and when bypass ignition is performed. This has the effect of providing an internal combustion engine control device that can save power.

[Brief explanation of drawings]

FIG. 1 is a perspective view showing a rotation signal generator used in an embodiment of the present invention, FIG. 2 is a waveform diagram showing a crank angle reference signal and a cylinder identification signal generated by an embodiment of the invention, and FIG. FIG. 3 is a waveform diagram showing a bypass ignition operation according to an embodiment of the present invention, FIG. 4 is a block diagram showing a general internal combustion engine control device, and FIG. 5 is a rotation signal generation diagram used in a conventional internal combustion engine control device. 6 is a circuit diagram showing a position signal generator provided in a general rotation signal generator, and FIG. 7 is a diagram showing a crank angle reference signal and cylinder identification generated in a conventional internal combustion engine control device. FIG. 3 is a waveform diagram showing signals. (8) Rotation signal generator (10) Microcomputer Pl... First pulse P2... Second pulse B75°... First reference position B5°... Second reference Position B110°...Third reference position B40°...Fourth reference position Ll...Crank angle reference signal L2...Cylinder identification signal In the drawings, the same reference numerals indicate the same or corresponding parts.

Claims (1)

[Claims] A plurality of cylinders that rotationally drive an internal combustion engine, and a plurality of cylinders that are reversed in correspondence with a first reference position that serves as a control reference for each cylinder and a second reference position that serves as a bypass ignition timing. a rotation signal generator that generates a crank angle reference signal consisting of a pulse train in synchronization with the rotation of the internal combustion engine; a microcomputer that controls the operation of each cylinder based on the first and second reference positions; In the internal combustion engine control device, the crank angle reference signal is a first reference signal that is inverted at a third reference position that is more advanced than the first reference position with respect to the ignition cycle of each cylinder. An internal combustion engine control device comprising: a pulse; and a second pulse that is reversed at a fourth reference position that is retarded from the first reference position and advanced from the second reference position. .