JP2834371B2 - Internal combustion engine 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 internal combustion engine control apparatus for controlling fuel injection and ignition timing for each cylinder based on reference position signals indicating first and second reference positions, and more particularly, to controlling timing control accuracy. The present invention relates to an improved internal combustion engine control device.

[0002]

2. Description of the Related Art Generally, in an internal combustion engine such as an automobile engine, it is necessary to optimally control fuel injection and ignition timing according to operating conditions. Therefore, a microcomputer for recognizing a crank angle reference position for each cylinder, calculating ignition timing, fuel injection timing, and the like and performing timer control is used.

FIG. 3 is a block diagram showing a conventional internal combustion engine control apparatus. In the figure, reference numeral 1 denotes a first and a second reference position (described later) of each cylinder in synchronization with the rotation of the internal combustion engine. A reference position signal generating means for generating a reference position signal Tθ, various sensors for detecting an operation state D of the internal combustion engine,
Reference numeral 3 denotes control means for controlling the internal combustion engine based on the reference position signal Tθ and the operating state D.

The control means 3 comprises a microcomputer, recognizes a reference position of each cylinder based on a reference position signal Tθ, calculates an ignition timing or the like in accordance with an operating condition D, and controls each control signal corresponding to this. Is output.

The control means 3 includes a cycle measuring unit 31 for measuring a cycle T of each reference position in each predetermined section based on the reference position signal Tθ, and a cycle for calculating a cycle ratio R of each reference position in each predetermined section. A ratio calculation unit 32 and a timing control unit 33 that determines a specific cylinder based on the cycle ratio R and controls the internal combustion engine based on the operating state D and the reference position signal Tθ. A control signal from the control means 3 is applied to an ignition coil, an injector, and the like (not shown).

FIG. 4 is a perspective view showing a specific structure of the reference position signal generating means 1. Reference numeral 10 denotes a cam shaft which rotates in synchronization with rotation of the internal combustion engine, and 11 denotes a cam shaft which is fixed to the cam shaft 10 and is synchronized with the internal combustion engine. This is the signal board that rotates. 12 is a plurality of slits formed concentrically along the rotation direction of the signal plate 11, the front end of each slit 12 corresponds to the first reference position of each cylinder,
The rear end corresponds to the second reference position. Although not shown here, only one front end of the slit 12 corresponding to a specific cylinder has an offset.

[0007] 13 is a light emitting element comprising a photodiode,
Numeral 14 denotes a light receiving element composed of a phototransistor, which constitutes a photocoupler arranged opposite to the slit 12 for generating the reference position signal Tθ, and generates a reference position signal Tθ every time the slit 12 faces the slit 12. ing.

FIG. 5 is a timing chart showing the reference position signal Tθ, where I is the waveform of the coil current flowing to the primary side of the ignition coil, Ta is the timer control time for the ignition timing, and θa
Is a crank angle corresponding to the timer control time Ta.

In the reference position signal Tθ, B65 ° (TD
Crank angle 65 ° before C) is the first reference position,
It corresponds to the maximum advance control position of each cylinder, and is offset by a predetermined amount α (for example, 10 ° in crank angle) toward the advance side only for the specific cylinder # 2. B5 ° is a second reference position, which corresponds to the vicinity of the initial ignition position of each cylinder.

The reference position signal Tθ comprises a pulse which rises at a first reference position B65 ° for a non-specific cylinder and falls at a second reference position B5 °, and is offset by α with respect to a specific cylinder. And a pulse rising at the first reference position B75 ° and falling at the second reference position B5 °. In terms of the crank angle, the total cycle of the four cylinders of the reference position signal Tθ is 720 °, the pulse cycle T180 for each first reference position is 180 °, and the second cycle from the first reference position B65 ° is the second cycle. The pulse period T60 up to the reference position B5 ° is 60 °,
The pulse period T120 from the second reference position B5 ° of a certain cylinder to the first reference position B65 ° of the next cylinder is 120 °.

Next, referring to FIGS. 4 and 5, FIG.
The operation of the conventional internal combustion engine control device shown in FIG. When the internal combustion engine rotates, the rotation of the camshaft 10 causes the reference position signal generation means 1 to generate the reference position signal Tθ as shown in FIG.
And the various sensors 2 generate various operating states D,
These reference position signal Tθ and operating state D are
Is input to

The control means 33 recognizes the reference position of each cylinder and each cylinder to be controlled based on the reference position signal Tθ, and calculates a control timing such as an ignition timing according to the operating state D. A control signal corresponding to the fuel injection timing is output. Normally, in the case of the ignition control, when the ignition timing is on the advance side, the timer control based on the first reference position B65 ° is performed, and when the ignition timing is on the retard side, the second reference position B is used.
Timer control based on 5 ° is performed. The power distribution to each cylinder is performed by a discharge electrode (not shown) provided on the rotating shaft.
Is done mechanically via

At this time, the cycle measuring unit 31 measures the pulse cycle T180 of the reference position signal Tθ and the H level period cycle T60 of each pulse, and the cycle ratio calculating unit 32 calculates the cycle T180 and T
A ratio R of 60 is calculated, and the timing control unit 33 determines that the cylinder is a non-specific cylinder if the period ratio R is (T60 / T180), and determines a specific cylinder if the period ratio R is (T70 / T180). Also, the timing control unit 33
Calculates the ignition timing and the fuel injection timing based on the operating state D and the reference position signal Tθ, and outputs control signals for the ignition coil and the injector.

However, depending on the manufacturing accuracy of the slit 12 formed on the signal plate 11 and the mounting accuracy of the photocouplers 13 and 14, etc., the reference position B indicated by the reference position signal T.theta.
65 ° and B5 ° include an error. Among them, the second reference position B5 ° can be adjusted by a forced ignition test or the like in an assembly stage, but the first reference position B65 ° includes the above-described error. Normally, due to the limit of the manufacturing accuracy of the slit 12, the crank angle 60 ° of the pulse period T60 includes an error of ± 2 ± 3 °. When the first reference position B65 ° including the error is used as the timing control reference, the internal combustion engine cannot be driven accurately and efficiently.

[0015]

As described above, the conventional internal combustion engine control apparatus uses the reference position based on the reference position signal T.sub.θ including the error as the reference for timing control, and thus depends on the accuracy of the reference position signal T.sub.θ. There is a problem that a control error occurs.

SUMMARY OF THE INVENTION The present invention has been made to solve the above problems, and an object of the present invention is to provide an internal combustion engine control device capable of correcting an error of a reference position signal and performing highly accurate timing control. .

[0017]

According to the present invention, there is provided an internal combustion engine control apparatus comprising: a cycle measuring section for measuring a predetermined section cycle and one rotation cycle of each reference position; and a cycle for calculating a cycle ratio based on the predetermined section cycle. A ratio calculation unit, a steady operation determination unit that determines a steady operation state of the internal combustion engine based on one rotation cycle and generates a steady operation signal, and that is responsive to the steady operation signal and based on a predetermined section cycle and one rotation cycle. a reference position correction unit for generating a correction signal to the reference position signal, the reference position signal, the operating state, viewed contains a timing control unit for controlling the internal combustion engine based on the cycle ratio and the correction signal, the first reference position
Position corresponds to the maximum advance control position of each cylinder, and the second reference position
Position corresponds to the vicinity of the initial ignition position of each cylinder.
The section cycle is the generation interval of the first reference position or the second reference position.
A first interval cycle consisting of position occurrence intervals and a first reference
A second interval consisting of an occurrence interval between the position and a second reference position.
And the period ratio is the first period period and the second period period.
It consists of a ratio with the section cycle .

[0018]

According to the present invention, the crank angle of the pulse cycle of the reference position signal is corrected based on the cycle ratio during the steady operation in which the rotation speed is constant, and the timing control based on the accurate crank angle reference position is enabled.

[0019]

【Example】

Embodiment 1 FIG. Hereinafter, a first embodiment of the present invention will be described with reference to the drawings. FIG. 1 is a block diagram showing a first embodiment of the present invention, wherein 1, 2 and 32 are the same as those described above. Also, 3A,
31A and 33A correspond to the control unit 3, the cycle measuring unit 31, and the timing control unit 33, respectively. In this case, the cycle measuring unit 31A measures not only the predetermined section cycle T but also one rotation cycle T 'corresponding to N rotations of the internal combustion engine.

Reference numeral 34 denotes a steady operation determining unit which determines a steady operation state of the internal combustion engine based on one rotation period T 'and generates a steady operation signal F. 35 responds to the steady operation signal F and has a predetermined period T and Reference position signal Tθ based on one rotation cycle T ′
Is a reference position correction unit that generates a correction signal C for
The timing control unit 33A controls the internal combustion engine based on the reference position signal Tθ, the operating state D, the cycle ratio R, and the correction signal C.

FIG. 2 is a timing chart for explaining the operation of the first embodiment. T720 (n) is a reference position signal Tθ.
One rotation cycle based on the rise of the same pulse of T720
(n-1) is the previous one rotation cycle, and θ is the crank angle corresponding to the pulse cycle T60 in one H level section.

Next, the operation of the first embodiment of the present invention shown in FIG. 1 will be described with reference to FIG. First, with the rotation of the internal combustion engine, a reference position signal Tθ composed of a pulse as shown in FIG. 2 is input to the cycle measuring unit 31A and the timing control unit 33A in the control unit 3A.

The cycle measuring unit 31A measures the cycle T180 of the second reference position B5 ° at each fall of the reference position signal Tθ and each pulse cycle T60 as a predetermined section cycle T, and also measures one rotation cycle T720 of the same pulse. (n-1), T720 (n), ...
Is measured as one rotation cycle T ′. Period ratio calculator 32A
Calculates the cycle ratio R (= T60 / T180) based on the predetermined section cycle T as described above.

Further, the steady operation determining section 34 determines one rotation cycle T '.
In order to determine the steady operation state based on the above, the difference between the previous and current one rotation cycle T720 (n-1) and T720 (n) is compared with a predetermined value To as follows.

| T720 (n) −T720 (n−1) | ≦ To (1)

If the absolute value of one rotation cycle difference is a predetermined value To
When the following expression (1) is satisfied, the steady operation signal F is generated on the assumption that the rotation speed of the internal combustion engine is stable.

In response to the steady operation signal F, the reference position corrector 35 calculates the crank angle θ of the pulse cycle T60 in the H level section based on the predetermined section cycle T and one rotation cycle T ', and corrects it. The signal C is input to the timing controller 33A. That is, an accurate crank angle θ is obtained by calculation as follows.

Θ = {T60 / T720 (n)} × 720 (2)

From the equation (2), the crank angle θ corresponding to the actual pulse width including the error is obtained. As a result, the timing control unit 33A obtains the first and second reference positions B65 ° and B5 ° in which the error has been corrected based on the correction signal C indicating the crank angle θ, the reference position signal Tθ, and the cycle ratio R. And the timing control signal does not include an error.

Also, instead of equation (2), one rotation cycle T720 (n)
And the following equation based on T720 (n-1) and T720 (n-1).

Θ = {T60 / [T720 (n) + T720 (n-1)]} × 1440 (3)

According to the equation (3), the crank angle θ is corrected by the two one rotation periods T720 (n) and T720 (n-1), so that higher accuracy is realized. Here, the crank angle θ of the pulse cycle T60 for the non-specific cylinder is corrected, but it is needless to say that the crank angle of the pulse cycle T70 for the specific cylinder can be similarly corrected.

Here, since it is a well-known technique, it is particularly described.
However, the reference position signal generating means 1 does not
When mounting on a rank shaft, the first or
Is B65 ° or B5 ° with respect to the second reference position (usually
Is positioned so as to coincide with the second reference position B5 °).
It is well known to be. Therefore, the above correction processing
Can accurately correct the reference position of all cylinders
it is obvious. In addition, as the cycle ratio of the predetermined section cycle,
The generation interval of the first reference position B65 ° is defined as a first section cycle.
And from the first reference position B65 ° to the second reference position B5 °
Is the second interval cycle, and the second interval cycle
Was divided by the first interval period, but any interval
The period can be determined and used as the period ratio. For example,
The generation interval of the second reference position B5 ° is defined as a first section cycle,
From the second reference position B5 ° to the first reference position B65 °
May be set as the second interval cycle, and the cycle ratio
The same operation and effect can be obtained even if the rate is set to the reciprocal. Furthermore, the first
Is not affected by the offset of a specific cylinder
Needless to say, it is calculated based on the pulse edge of
Nor. Embodiment 2. FIG. In the first embodiment, the case of four cylinders has been described, but the internal combustion engine of another number of cylinders may be controlled.

[0034]

As described above, according to the present invention, a cycle measuring section for measuring a predetermined section cycle and one rotation cycle of each reference position, and a cycle ratio calculating section for calculating a cycle ratio based on the predetermined section cycle. A steady operation determining unit that determines a steady operation state of the internal combustion engine based on one rotation cycle to generate a steady operation signal, and that responds to the steady operation signal and performs a predetermined section cycle and a reference position signal based on one rotation cycle. a reference position correction unit for generating a correction signal, the reference position signal, the operating state, based on the cycle ratio and correction signal and a timing controller for controlling an internal combustion engine, the first reference position is maximum advance of each cylinder
Corresponding to the angle control position, the second reference position is the initial position of each cylinder.
The predetermined section cycle corresponds to the vicinity of the
From the occurrence interval of the reference position or the occurrence interval of the second reference position
A first interval period, a first reference position, and a second reference position
A second interval cycle consisting of an occurrence interval between
Is the cycle ratio the ratio between the first section cycle and the second section cycle?
Since the crank angle of the pulse cycle of the reference position signal is corrected based on the cycle ratio during the steady operation , there is an effect that an internal combustion engine control device capable of performing highly accurate timing control is obtained.

[Brief description of the drawings]

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

FIG. 2 is a timing chart for explaining the operation of the first embodiment of the present invention.

FIG. 3 is a block diagram showing a conventional internal combustion engine control device.

FIG. 4 is a perspective view showing a general reference position signal generating means.

FIG. 5 is a timing chart showing the operation of a conventional internal combustion engine control device.

[Explanation of symbols]

 1 Reference position signal generation means 2 Various sensors 3A control means 31A Period measurement unit 32 Period ratio calculation unit 33A Timing control unit 34 Steady operation determination unit 35 Reference position correction unit Position signal B65 ° First reference position B5 ° Second reference position T Predetermined section cycle T 'One rotation cycle

Claims (1)

(57) [Claims] 1. The first cylinder of each cylinder is synchronized with rotation of an internal combustion engine.
And a reference position signal generating means for generating a reference position signal corresponding to the second reference position; various sensors for detecting an operating state of the internal combustion engine; and the internal combustion engine based on the reference position signal and the operating state. Control means for controlling, the control means comprises: a cycle measuring unit for measuring a predetermined section cycle and one rotation cycle of each of the reference positions; and a cycle ratio calculating unit for calculating a cycle ratio based on the predetermined section cycle. A steady operation determining unit that determines a steady operation state of the internal combustion engine based on the one rotation cycle to generate a steady operation signal; and that is responsive to the steady operation signal and based on the predetermined section cycle and the one rotation cycle. A reference position correction unit that generates a correction signal for the reference position signal; and the internal combustion engine based on the reference position signal, the operating state, the cycle ratio, and the correction signal. Includes a timing controller for controlling the said first reference position, the maximum advance angle control position of the respective cylinders
And the second reference position is an initial ignition position of each of the cylinders.
Corresponding to the vicinity of the first reference position, the predetermined section cycle is the generation interval of the first reference position or
Is the circumference of a first section consisting of the generation intervals of the second reference position.
Period, and between the first reference position and the second reference position
And a second section cycle consisting of occurrence intervals of the first section cycle and the second section cycle.
An internal combustion engine control device characterized by a ratio with a cycle .