JPH04148043A - Internal combustion engine control device - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

Detailed Description of the Invention [Industrial Field of Application] The present invention relates to a control device for an internal combustion engine that controls each cylinder based on an angle signal from an angle signal generator, and in particular to an engine standard in a practical control range. Internal combustion engine control bag that improves system control reliability by detecting position! It is related to.

[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 rotationally driven at approximately 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 172 cycles. 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 174 cycles.

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.1 Normally, the means for generating the crank angle reference signal corresponding to the reference position of each cylinder is the camshaft or crankshaft of the internal combustion engine. A rotation signal generator is used to detect the rotation of the motor.

Figure 8 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. The 0 position signal, which is an interface circuit for the engine, includes a cylinder identification signal and a crank angle reference signal (described later).

(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. 9 is a perspective view showing a specific configuration example of a rotation signal generator (8) used in a conventional internal combustion engine control device, and FIG. 10 is a position signal generator provided in the rotation signal generator (8). FIG.

In FIG. 9, (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 cycle of 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.

Here, a case is shown in which the internal combustion engine has 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 the good intention (3a) with respect to 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 the good intentions (3 turtles) and (3b), respectively, and (5a) and (5b) are 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 (5&) and (5b) constitute two sets of photocouplers.

In FIG. 10, light emitting diodes (4a) and (4b
) and photodiodes (5a) and (5b) are typically shown as (4) and (5), with only one photocoupler being shown. (6) is an amplifier circuit that amplifies the output signal from the photodiode (5);
) is an open 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. 8).

Next, while referring to the waveform diagram in FIG.
The operation of the conventional internal combustion engine control device shown in FIG.

When the rotating shaft (1) and the rotating disk (2) rotate in synchronization with the internal combustion engine, the photodiodes (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 amplifier circuit (6) and a transistor (7), and is passed through an interface circuit (9) to a microcomputer (1).
G).

As shown in FIG. 11, the position signal includes a crank angle reference signal 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 at the first reference position (B75°) and the second reference position (B5°) for each cylinder #1 to #4. This results in multiple inverted pulse trains.

The rising edge (875°) of each pulse is the TD for 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 driving.
The falling edge (B5°) indicates a position 5° before TDC, and is the bypass ignition timing at startup when the microcomputer (10) cannot operate.

On the other hand, the cylinder identification signal obtained based on the window (3b),
is a pulse corresponding only to the crank angle reference signal L+ of a specific cylinder, that is, #1 cylinder, and is used to identify the specific cylinder. The cylinder identification signal RI is in phase with the crank angle reference signal L1, and in this case, the crank angle reference signal L
It rises before the + rise (B75°) and falls after the fall (B5°).

The operating position of each cylinder identified by the crank angle reference signal is shifted by 174 cycles with respect to one cycle of the camshaft (corresponding to two cycles of the crankshaft, that is, 720°), 1/2 period (180°
), and each cylinder is shifted by #1, as is well known.
The cylinders operate in the order of cylinder #3, cylinder #4, and cylinder #2.

The crank angle reference signal L+ and QWI! obtained in this way!
Based on the lI-specific signal Lx, the microcomputer (1
0) identifies a specific cylinder and the operating position of each cylinder, and calculates and controls the energization start timing, ignition timing, fuel injection, etc. For example, the timer is After a predetermined period of time has elapsed, energization starts.
It is controlled to ignite after a predetermined period of 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 B75°, it is necessary to form a long window (3 &) on the rotating disk (2), which deteriorates the strength of the rotating disk (2). Furthermore, during bypass ignition, the first reference position B75° is the energization start time, and the second reference position B 85° is the ignition timing.
If the energization time becomes longer due to the advance angle of the first reference position, power consumption increases and problems such as heat generation occur, which is impractical.Furthermore, if the control angle from the reference position increases, Since it is greatly affected by disturbances such as fluctuations, it becomes impossible to stably control the system.

[Problems to be Solved by the Invention] As described above, in the conventional internal combustion engine control device, the reference signal that serves as the reference for determining the ignition timing and fuel injection timing of the engine is generated from a rotation signal generator attached to the camshaft. However, since the camshaft is driven by the crankshaft as well as a belt, there may be a phase shift depending on the operating condition of the engine, which may result in a difference in the desired performance when using this signal to control engine operation. There was a problem in that it was not possible to obtain In order to solve this problem, a method of attaching the above-mentioned rotational signal generator to the crankshaft has been devised, but this method has the problem of a complicated structure and an increase in cost. Further, in a four-stroke engine, it is impossible to identify each individual cylinder using only information obtained from the crankshaft, and there is a problem in that a separate means for cylinder identification must be provided.

This invention was made in order to solve the above-mentioned problems. A one-channel signal generator is attached to the crankshaft, and the reference position and angle of the engine are detected simultaneously to control the internal combustion engine and to control the internal combustion engine. It is an object of the present invention to provide a control device for an internal combustion engine in which a separate signal generating means is provided on the camshaft or a corresponding shaft, and a specific cylinder can be identified using the signal generated by the signal generating means.

[Means for Solving the Problems] A control device for an internal combustion engine according to the present invention includes an engine angle detection means for detecting a rotation angle of a crankshaft of an internal combustion engine, and a target ignition control position based on operating conditions of the internal combustion engine. and a calculation means for calculating the fuel injection position, and a control means for controlling the control position by the calculation means based on the output signal of the engine angle detection means, a discontinuous part and a second discontinuous part whose polarity is different from the discontinuous part, the first and second discontinuous parts are set at predetermined reference positions of the engine, and the engine is controlled based on the reference position. It was designed to do this.

[Operation] In the present invention, a first discontinuous portion and a second discontinuous portion having a different polarity are provided in the angle signal from the engine angle detection means for detecting the rotation angle of the crankshaft of the internal combustion engine.

The first and second discontinuous portions are then set as predetermined reference positions of the engine, and the engine is controlled based on these reference positions.As a result, the desired performance can be obtained, and the structure is simple and inexpensive. Become something.

[Example] Hereinafter, an example of the present invention will be described with reference to the drawings. 1st
The figure is a block diagram showing one embodiment of the present invention. In the figure, (11) is provided on the crankshaft of the engine, and the second
(An angle signal generator that generates an angle signal (POS) as shown in M (a), (12) is provided on the camshaft to identify a specific cylinder, a cylinder identification signal generator (13) that generates an identification signal (SGC);
) are other sensors, and (14) is a microcomputer. The microcomputer (14) includes a reference position detection section (14a) to which the angle signal from the angle signal generator (11) is supplied, a starting ignition position detection section (14b), a target control position calculation section (14c), and a reference position detection section (14c). Position detection unit (14a
), a rotation period calculation section (14d), a target control position calculation section (14c), and a rotation period calculation section (14
a control time calculation unit <14e) to which the output of d) is supplied;
Starting ignition position detection section (14b) and control time calculation section (
a selection section (14f) to which the output of 14e) is supplied, a reference position detection section (14a) and a starting ignition position detection section (14b) to which a cylinder identification signal is supplied from the cylinder identification signal generator (12). The cylinder identification unit (14
g).

(15) is the output terminal of the selection section (14f>), (16) is the output terminal of the cylinder identification section (14g).
The output of step 3) is supplied to the target control position calculation section (14c).

45th! As shown in i, the angle signal detector (11) is attached to the crankshaft (17), and the cylinder identification signal generator (
12) is attached to the camshaft (18). As shown in Fig. 5, the crankshaft (17) has a gear (19) on its outer periphery, and a predetermined portion of the gear (19) has a tooth extraction portion (20).
A raised tooth portion (21) is provided. If the angle signal generator (11) is placed close to such a gear (19), the angle signal generator (11) will emit the signal shown in FIG. 2(a).
), the tooth extraction as shown in FIG. can get. In this way, the angle signal is provided with a first discontinuous portion and a second discontinuous portion at a portion corresponding to a predetermined reference position so that the engine reference position (ref) can be detected. It is possible to detect the reference position and engine angle.

Next, the operation of the embodiment of the present invention shown in FIG. 1 will be explained. When the above-mentioned angle signal is supplied from the angle signal generator (11) to the reference position detector (14a), the reference position detector (14a) detects the input period of the angle signal as shown in FIG. Compare the size and find the first discontinuous part (
22) detecting a first reference position (ref). The signal regarding this first reference position is generated by the rotation period calculation section (
14d), where the rotation period T between the reference positions is determined based on the first reference position, and the control time calculation unit (
14e). Further, the angle signal from the angle signal generator (11) is supplied to the target control position calculating section (14c,), which calculates the target control position f based on the first reference position.
P is required. The difference between this target control position tp and the first reference position (ref) is the angle a, which is supplied to the control time calculation section (14e). The control time calculating section (14e) calculates the control time t from the first reference position to the target control position according to the following equation.

tg=α·T/180 (sec) The signal of this control time t is supplied to the selection section (14f).

Further, when the angle signal from the angle signal generator (11) is supplied to the starting ignition position detecting section (14b), this starting ignition position detecting section (14b) performs the same procedure as shown in FIG. The magnitude of the input period of the angle signal (inverted signal) is compared at , and the starting ignition position (in
i) Detect (second reference position). This signal regarding the starting ignition position is supplied to the selection section (14f) and is selected together with the signal regarding the previous control time. Therefore, the ignition timing and fuel injection timing of the engine are determined based on this control time t and the starting ignition position (ini).

A cylinder identification signal as shown in FIG. 2(C) is supplied to a cylinder identification section (14g) from a cylinder identification signal generator (12) attached to a 1/2 rotation shaft, that is, a camshaft (18).

In addition, this cylinder identification section (14g) includes a reference position detection section (14g).
4a) and the starting ignition position detection unit (14b) respectively supply signals regarding the first reference position and the starting ignition position.

A cylinder identification signal for detecting a specific cylinder of the engine is generated in each angle signal section, and the number of pulses of the signal is set to be different for each cylinder.

This cylinder identification operation will be explained with reference to FIG.

Cylinder identification section (14g) of microcomputer (14)
detects the number of cylinder identification signals in the reference position section based on the first reference position from the reference position detection section (14a) (step 51). Next, the number of cylinder identification signals in the reference position section obtained in step S1 is detected. By comparing the number of identification signals with the cylinder reference pulse number stored in advance, the cylinder corresponding to the matched pulse number is determined to be the identified cylinder.Step S2)
, the identified cylinder is set in the register (not shown) of the cylinder identification unit (14g) (step S3).The setting position of the cylinder identification signal is offset by a predetermined angle from the first reference position, so that the engine An angular margin is ensured so that even if a mechanical transmission system error (angular phase) occurs between the crankshaft and the camshaft, the cylinder identification signal is detected in the reference position section.

Here, the width of the discontinuous part of the angle signal may be changed for each ignition cylinder group, and the ignition cylinder group may be identified by detecting the width. In addition, if the angle signal generator is a Hall type, the discontinuous part By changing the signal level between "H" and "L", it is possible to identify the ignition cylinder group. Furthermore, engine angular velocity fluctuations can be detected based on the number of pulses of the angle signal input within a predetermined time from the reference position.

In this way, in this embodiment, the crankshaft and camshaft sensors, that is, the angle signal generator, and the cylinder identification signal generator can be configured with inexpensive magnetic sensors. Moreover, since it is a period counting method, the software burden on the control unit is small, and the control resolution does not depend on the number of pulses of the angle signal.

FIG. 7 is an explanatory diagram showing a second embodiment of the present invention. In this embodiment, the cylinder identification signal (SGC) is as shown in FIG. That is, for example, the first reference position (
ref) In the leap, the first discontinuous portion (22) rises with a slight delay from the first reference position, which is the rise position,
A long-width first pulse P1 that falls at the falling edge of the second discontinuous portion (23) and a short-width second pulse P that is formed with a slight delay from this are inserted, and the next first pulse P1 is inserted. Only the first pulse P1 is inserted between the reference positions.

The specific cylinder is identified by the number of pulses of the cylinder identification signal input between the reference positions, as in the above embodiment. still,
In this case, the falling point of the first pulse P is the starting ignition position (ini), so the backup circuit (
(not shown), so-called bypass ignition is performed using this cylinder identification signal.

Further, the ignition cylinder group is identified in the same manner as in the first embodiment.

In this way, in this embodiment, the crankshaft and camshaft sensors, that is, the angle signal generator, and the cylinder identification signal generator can be configured with inexpensive magnetic sensors. In addition, because of the period counting method, the software load on the control section is small, the control resolution does not depend on the number of pulses of the angle signal, and a backup circuit can be easily configured.

[Effects of the Invention] As described above, according to the present invention, the engine angle detection means detects the rotation angle of the crankshaft of the internal combustion engine, and the target ignition control position and the fuel injection position are determined based on the operating conditions of the internal combustion engine. and a control means for controlling the control position by the calculation means based on the output signal of the engine angle detection means; A second discontinuous portion having a polarity is provided, the first and second discontinuous portions are set as predetermined reference positions of the engine, and the engine is controlled based on the reference position. Therefore, it is possible to provide a control device for an internal combustion engine that can easily obtain the desired performance, has a simple and inexpensive structure, and can easily identify a specific cylinder without providing a separate cylinder identifying means. It has the effect of

[Brief explanation of the drawing]

1st rI! I is a block diagram showing an embodiment of the present invention;
2 and 3 are diagrams for explaining the operation of this invention, FIGS. 4rjA and 5 are structural diagrams showing the main parts of this invention, and FIG. 6 is a flowchart for explaining the operation of this invention. , 71st! I is an explanatory diagram showing other embodiments of the present invention, FIG. 8 is a block diagram showing a conventional internal combustion engine control device, and FIG. 9 is a rotation signal generator used in a conventional internal combustion engine control device. FIG. 10 is a circuit diagram showing a position signal generator provided in a general rotation signal generator, and FIG. 11 is a crank angle reference signal and cylinder identification signal generated in a conventional internal combustion engine control device. FIG. In the figure, (11) is an angle signal generator, (12) is a cylinder identification signal generator, (14) is a microcomputer,
(17) is the crankshaft, (18) is the camshaft, -(19)
is the gear, (20) is the tooth extraction part, (21) is the tooth raising part, (
22) is the first discontinuous portion, and (23) is the second discontinuous portion. In the drawings, the same reference numerals indicate the same or corresponding parts.

Claims (2)

[Claims] (1) Engine angle detection means for detecting the rotation angle of the crankshaft of the internal combustion engine; calculation means for calculating the target ignition control position and fuel injection position based on the operating conditions of the internal combustion engine; control means for controlling the control position by the calculation means based on the output signal, the angle signal of the engine angle detection means being provided with a first discontinuous portion and a second discontinuous portion having a different polarity from the first discontinuous portion; A control device for an internal combustion engine, characterized in that the first and second discontinuous portions are set at predetermined reference positions of the engine, and the engine is controlled with reference to the reference positions. (2) Provide cylinder identification signal generating means for generating a cylinder identification signal for each cylinder of the engine in accordance with the rotation of a rotating shaft that rotates at a ratio of 1/2 to the rotation of the crankshaft, and between the reference positions 2. A control device for an internal combustion engine according to claim 1, wherein a cylinder of the engine is identified from the output signal of the cylinder identification signal means generated.