JPH0510229A - Ignition controller for internal combustion engine - Google Patents

Abstract

PURPOSE:To obtain an ignition controller for an internal combustion engine which speedily generates the correct standard position signal for each cylinder and can perform the cycle measurement electronic advance angle control with high precision. CONSTITUTION:An ignition controller is equipped with a cylinder discriminating signal generator 1A which is installed on a camshaft and generates a cylinder discriminating signal SC' and a standard position pulse generator 6 which is installed on a crankshaft and generates a standard position pulse P. Further, the controller is equipped with a standard position signal generating circuit 8 which generates a standard position signal ST' corresponding to each cylinder and the cylinder discriminating information C on the basis of the cylinder discriminating signal and the standard position pulse and a microcomputer 5A which calculation-controls the ignition timing for each cylinder on the basis of the standard position signal and the cylinder discriminating information. The cylinder discriminating, signal is the pulse corresponding to a second standard position of each cylinder other than a specific cylinder, and the standard position pulse is set so that the numbers of pulses corresponding to the second standard position many vary with cylinder groups.

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 ignition control device for controlling the ignition timing (energization and interruption of an ignition coil) of each cylinder based on a reference position signal synchronized with the rotation of a crankshaft, and more particularly to a reference position. The present invention relates to an internal combustion engine ignition control device that realizes high precision signals.

[0002]

2. Description of the Related Art Generally, in an internal combustion engine having a crankshaft driven by a plurality of cylinders and a camshaft interlocked with the crankshaft, the internal combustion engine is controlled in order to control ignition timing and fuel injection of each cylinder. A reference position signal synchronized with the rotation is used. The reference position signal indicates a reference position corresponding to the rotation angle of the crank shaft (hereinafter referred to as the crank angle), and the reference position signal generator is provided on the crank shaft or a cam shaft that is interlocked with the crank shaft.

FIG. 3 is a block diagram showing a conventional internal combustion engine ignition control apparatus. In the figure, 1 is a camshaft (not shown).
A cylinder identification signal generator 2 for generating a cylinder identification signal SC and a reference position signal ST for indicating a first and second reference position corresponding to a predetermined crank angle on a camshaft.
A reference position signal generator 3 and 4 for processing and sending the cylinder identification signal SC and the reference position signal ST respectively, and 5 for each cylinder based on the cylinder identification signal SC and the reference position signal ST. It is a microcomputer (hereinafter referred to as a microcomputer) that controls the ignition timing.

Normally, the cylinder identification signal generator 1 and the reference position signal generator 2 are provided on a cam shaft which makes one rotation for every two revolutions of the crankshaft, and the cylinder identification corresponding to the reference position for each cylinder. The signal SC and the reference position signal ST are generated. For example, on a disc that rotates integrally with a cam shaft, arc-shaped slits corresponding to a predetermined crank angle are provided as reference positions for the number of cylinders, and slits corresponding to specific cylinders are separately provided, and each slit is formed by a photocoupler or the like. The waveform shaping process may be performed after the detection.

FIG. 4 is a waveform diagram showing an example of the cylinder identification signal SC and the reference position signal ST, and shows a case where they are generated for four cylinders consisting of # 1 to # 4, for example. Here, the cylinder identification signal SC is generated corresponding to the # 1 cylinder and the # 4 cylinder, and the first and second reference positions indicated by the fall and rise of the reference position signal ST are
B (advance from TDC) 5 ° and B75 °, respectively.

Next, the operation of the conventional internal combustion engine ignition control system shown in FIG. 3 will be described with reference to FIG.
The microcomputer 5 takes in the cylinder identification signal SC and the reference position signal ST from the cylinder identification signal generator 1 and the reference position signal generator 2 via the interfaces 3 and 4, and outputs the first reference position B5 for each cylinder. ° and second reference position B 75 °
To detect. Then, with reference to each reference position B5 ° or B75 °, the ignition timing and the fuel injection control position are controlled by the timer control so as to be optimum according to the operating state at that time (the internal combustion engine speed, load, etc.). To decide.

For example, the ignition timing is controlled to the retard side during low speed (low load) operation, and the ignition timing is controlled to advance (electronic advance) during high speed (high load) operation. Also, in the unstable control region such as the initial start-up of the internal combustion engine, for each cylinder,
The second reference position B75 ° is the forced energization start timing, and the first reference position B5 ° is the forced ignition timing. As a result, the energization time is secured to obtain the discharge energy enough to cause explosive combustion in the cylinder, and an explosion occurs at the timing when a predetermined torque is generated according to the operating region, ensuring a minimum internal combustion engine operation. To be done.

However, since the crank shaft and the cam shaft are connected by a timing belt or the like, each signal generator 1
The cam shaft provided with Nos. 2 and 2 is not necessarily synchronized with the rotation of the crank shaft with certainty, and an error occurs in the reference position signal ST.

[0009]

As described above, the conventional internal combustion engine ignition control device uses the first and second reference positions based on the reference position signal ST from the reference position signal generator 2 provided on the camshaft. Since the positions B5 ° and B75 ° are detected, there is a problem that an error occurs and the control cannot be performed with high precision.

The present invention has been made to solve the above-mentioned problems, and an internal combustion engine capable of generating an accurate reference position signal for each cylinder at an early stage and performing highly accurate cycle measurement electronic advance control. An object is to obtain an engine ignition control device.

[0011]

An internal combustion engine ignition control device according to the present invention is provided with a cylinder identification signal generator provided on a cam shaft for generating a cylinder identification signal, and a crank identification device having a predetermined crank angle provided on a crank shaft. A reference position pulse generator that generates a reference position pulse indicating the corresponding first and second reference positions, and a reference position signal and cylinder identification information corresponding to each cylinder based on the cylinder identification signal and the reference position pulse. A reference position signal generation circuit and a microcomputer for calculating and controlling the ignition timing for each cylinder based on the reference position signal and cylinder identification information are provided, and the cylinder identification signal corresponds to the second reference position of each cylinder except the specific cylinder. The number of pulses of the reference position pulse corresponding to the second reference position differs depending on the cylinder group.

Further, in the internal combustion engine ignition control device according to the present invention, the cylinder identification signal is a pulse corresponding to the second reference position of each cylinder and having a different pulse width only for the specific cylinder.

[0013]

According to the present invention, the cylinder identification signal which is related to the rotation of the cam shaft and which has a different pulse only for a specific cylinder, and the number of pulses of the second reference position which is related to the rotation of the crank shaft are the cylinder group. Thus, a highly accurate reference position signal is obtained early from different reference position pulses, and highly accurate ignition control is performed based on this reference position signal.

[0014]

DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described below with reference to the drawings. FIG. 1 is a block diagram showing an embodiment of the present invention, and 1A and 5A correspond to the cylinder identification signal generator 1 and the microcomputer 5, respectively.

Reference numeral 6 is a reference position pulse generator such as an electromagnetic pickup provided on the crankshaft, and has first and second reference positions (B5 ° and B75) corresponding to a predetermined crank angle.
The reference position pulse P indicating (°) is generated. Reference numeral 7 is a waveform shaping circuit for converting the reference position pulse P into a rectangular wave P ', and 8 is a reference position signal ST' and cylinder identification information C corresponding to each cylinder based on the cylinder identification signal SC 'and the reference position pulse P'. 2 is a reference position signal generating circuit.

In this case, the cylinder identification signal SC 'is composed of a pulse corresponding to the second reference position B75 ° for identifying the reference position for each cylinder, and is assigned to the specific cylinder for identifying the specific cylinder. Only the pulse is missing.
Further, the reference position signal generation circuit 8 generates cylinder identification information C in order to identify the reference position for each cylinder based on the cylinder identification signal SC 'and the reference position pulse P'.
And a reference position signal generator for generating the reference position signal ST ', and the cylinder identification information C and the reference position signal ST' are input to the microcomputer 5A.

The cylinder discriminating section 80 has a NAND gate 81 for taking a logical product of the cylinder discriminating signal SC 'and the reference position pulse P'.
A counter 82 that counts the output signal of the NAND gate 81 and a decoder 83 that generates, for example, 2-bit cylinder identification information C based on the count value of the counter 82 and the cylinder identification signal SC ′ are provided. Further, the reference position signal generating section 85 may include an edge identifying section for identifying each falling edge of the reference position pulse P ′, as well as a NAND gate and a counter similar to the cylinder identifying section 80.

Next, taking the case of four cylinders as an example, the operation of the embodiment of the present invention shown in FIG. 1 will be described with reference to the waveform chart of FIG. In addition, the ignition control device of FIG.
Since the reference position pulse P picked up from the crankshaft is used, and the stable reference position pulse P cannot be obtained in the low rotation operation region, the rotation speed is detected based on the cylinder identification signal SC ', and the predetermined rotation speed is detected. When it becomes above, it is designed to operate.

First, a reference position pulse generator 6 such as an electromagnetic pickup detects a reference position indicating member such as a magnetic body provided on a crankshaft and generates a reference position pulse P.
Since the reference position pulse P has a sine wave shape, it is shaped into a rectangular wave reference position pulse P ′ by the waveform shaping circuit 7, and then input to the reference position signal generation circuit 8 together with the cylinder identification signal SC ′.

In the reference position pulse P ', the number of pulses corresponding to the first reference position B5 ° is 1 regardless of the cylinder group, but the number of pulses corresponding to the second reference position B75 ° differs depending on the cylinder group. For example, it is 1 for the # 1 and # 4 cylinders and 2 for the # 2 and # 3 cylinders. Then, the falling timing of the first pulse with respect to each reference position is set to B75 ° and B5 °, respectively. In addition, the cylinder identification signal SC 'is a specific cylinder (here,
It consists of pulses corresponding to the second reference position B75 ° of each cylinder except the # 1 cylinder).

The reference position signal generator 85 in the reference position signal generation circuit 8 detects the level of the cylinder identification signal SC 'at each generation (falling) timing of the reference position pulse P'.
If the cylinder identification signal SC 'is at the H level (logic 1), the trailing edge of the reference position pulse P'at that time is set to the second level.
Cylinder identification signal S that follows the reference position B of 75 °
Even if the reference position pulse P'is generated during the H level section of C ', this is invalidated. Also, the cylinder identification signal SC 'is L
The fall of the reference position pulse P'after reaching the level (logic 0) is defined as the first reference position B5 °.

Thus, the reference position pulse P'generated first (when the count value of the counter 82 is 0) when the cylinder identification signal SC 'is at the H level, and when the cylinder identification signal SC' is at the L level. Each of the reference positions B75 ° and B5 ° is identified by the trailing edge of the reference position pulse P ′ generated in step S1. Therefore, as shown in FIG. 2, for example, it rises at the second reference position B75 ° and the first reference position B5 °.
The reference position signal ST ′ falling at
Generated from 85.

On the other hand, the cylinder identifying section 80 outputs the cylinder identifying signal S
The cylinder group is identified by counting the pulse number (falling number) of the reference position pulse P'while C'is at the H level. or,
When the cylinder identification signal SC 'is at the L level at the timing of the second reference position B75 ° of the reference position pulse P', the reference position pulse P'is identified as corresponding to the specific cylinder (# 1 cylinder).

That is, the NAND gate 81 in the cylinder identifying section 80.
Allows the reference position pulse P ′ to pass only when the cylinder identification signal SC ′ is at the H level, and the counter 82 causes the NAND gate 81
The reference position pulse P'passed through is counted. Next, the decoder 83 identifies each cylinder as described above based on the count value of the counter 82 and the cylinder identification signal SC ', and encodes the cylinder identification result into, for example, 2-bit data to obtain the cylinder identification information C. , At the timing of the first reference position B5 °, it is stored in the input port of the microcomputer 5A.

The microcomputer 5A uses the input cylinder identification information C
Is read at the timing of the second reference position B75 °, and cylinder identification is performed by software processing. The correspondence relationship between the cylinder identification information C and each cylinder at this time is, for example, as follows when the cylinder identification information C is 2 bits. Cylinder identification information Cylinder "1,1" → # 1 cylinder "1,0" → # 3 cylinder "0,1" → # 4 cylinder "0,0" → # 2 cylinder

As a result, the microcomputer 5A can identify the cylinder and the reference position early and perform the ignition control at the timing of the second reference position B75 °. At this time, since the reference position signal ST 'is completely synchronized with the rotation of the crankshaft, ideally, no detection error occurs at the reference positions B5 ° and B75 °.

Therefore, the cylinder identification signal SC 'which is related to the rotation of the camshaft and which is different only for the specific cylinder (# 1 cylinder) and the pulse of the second reference position which is related to the rotation of the crankshaft. A highly accurate reference position signal ST 'can be obtained at an early stage from a reference position pulse P'which varies in number depending on the cylinder group, and highly accurate ignition control can be performed based on the reference position signal ST'.

Once the cylinder identification information C is input,
The microcomputer 5A uses the reference position signal ST ′ that is continuously input.
Since the cylinder and the reference position can be sequentially identified based on the above, the cylinder identification information C is not always generated and the first 1
It may be generated only once.

In the above embodiment, the case where the pulse of the cylinder identification signal SC 'corresponding to the specific cylinder is omitted is shown.
Pulses having different pulse widths may be generated corresponding to a specific cylinder, such as the cylinder identification signal SC 'in FIG. In this case, the cylinder identification signal SC 'is similar to the above-mentioned embodiment in that it is composed of a pulse corresponding to the second reference position B75 ° of each cylinder, but only the specific cylinder (# 1 cylinder) is pulsed. The width is different.

In FIG. 3, for example, the pulse width for a specific cylinder corresponds to a crank angle of 25 °, and the pulse widths for other cylinders correspond to 35 °. Due to the difference in the pulse width of the cylinder identification signal SC ′, as described above,
The decoder 83 (see FIG. 1) can identify the specific cylinder and other cylinders, and the reference position signal generator 85 determines the reference position signal S
T'can be generated.

In each of the above embodiments, the case of four cylinders has been described as an example, but it goes without saying that the invention can be applied to an arbitrary plurality of cylinders of 6 cylinders or more. FIG. 4 is a waveform diagram showing an example of reference position pulses P and P'for a 6-cylinder internal combustion engine. Here, the case where the cylinder identification signal SC ′ is missing a pulse for a specific cylinder is taken as an example.
Further, the case where the reference position signal ST 'falls at the second reference position B75 ° and rises at the first reference position B5 ° is shown.

In this case, the number of reference position pulses P'for the second reference position B75 ° is 3, for cylinders # 6 and # 3, 1 for cylinders # 1 and # 4, and # 2. It is set to 2 for cylinders # 5 and # 5. As a result, the three cylinder groups can be individually identified, and the specific cylinder and the other cylinders can be individually identified by the cylinder identification signal SC '. At this time, the cylinder identification information C may be 3 bits, but if it is 2 bits, at least one cylinder can be specified, and for the remaining cylinders, each code can be associated with a cylinder group.

The number of each pulse of the reference position pulse P'is
The number of pulses is not limited to the example shown in FIG. 2 or FIG. 4, and can be set to any pulse number as long as the cylinder group and the reference position can be specified.

[0034]

As described above, according to the present invention, the cylinder identification signal generator provided on the cam shaft to generate the cylinder identification signal and the reference position pulse generation provided on the crank shaft to generate the reference position pulse. And a reference position signal generation circuit for generating a reference position signal and cylinder identification information corresponding to each cylinder based on the cylinder identification signal and the reference position pulse, and an ignition timing for each cylinder based on the reference position signal and the cylinder identification information. And a microcomputer for calculating and controlling the above, the cylinder identification signal is a pulse corresponding to the second reference position of each cylinder except the specific cylinder, and the reference position pulse is the number of pulses corresponding to the second reference position. Therefore, an internal combustion engine ignition control device capable of generating an accurate reference position signal for each cylinder at an early stage and capable of highly precise cycle measurement electronic advance control can be obtained. That.

Further, according to the present invention, the cylinder identification signal is
Since the pulse corresponding to the second reference position of each cylinder and having a different pulse width only for a specific cylinder is used, an accurate reference position signal for each cylinder is generated at an early stage, and highly accurate periodic measurement electronic advance control is performed. There is an effect that an internal combustion engine ignition control device capable of achieving the above can be obtained.

[Brief description of drawings]

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

FIG. 2 is a waveform diagram for explaining the operation of the apparatus of FIG.

FIG. 3 is a waveform diagram for explaining the operation of another embodiment of the present invention.

FIG. 4 is a waveform diagram for explaining the operation of the present invention in a 6-cylinder internal combustion engine.

FIG. 5 is a block diagram showing a conventional internal combustion engine ignition control device.

6 is a waveform diagram for explaining the operation of the apparatus of FIG.

[Explanation of symbols]

1A cylinder identification signal generator 5A microcomputer 6 Reference position pulse generator 8 Reference position signal generation circuit C cylinder identification information SC 'cylinder identification signal ST 'Reference position signal P, P'reference position pulse B5 ° First reference position B75 ° Second reference position

Claims (2)

[Claims] 1. An ignition control device for an internal combustion engine, comprising: a crankshaft driven by a plurality of cylinders; and a camshaft interlocking with the crankshaft, wherein the cylinder identification is provided on the camshaft and generates a cylinder identification signal. A signal generator; a reference position pulse generator provided on the crankshaft to generate a reference position pulse indicating first and second reference positions corresponding to a predetermined crank angle; the cylinder identification signal and the reference position; A reference position signal generation circuit that generates a reference position signal and cylinder identification information corresponding to each cylinder based on a pulse, and a microcomputer that arithmetically controls the ignition timing for each cylinder based on the reference position signal and the cylinder identification information. And the cylinder identification signal is a second cylinder of each cylinder except a specific cylinder.
Internal combustion engine ignition control device, wherein the number of pulses corresponding to the second reference position differs depending on the cylinder group. 2. An ignition control device for an internal combustion engine having a crankshaft driven by a plurality of cylinders and a camshaft interlocked with the crankshaft, wherein the cylinder identification is provided on the camshaft and generates a cylinder identification signal. A signal generator; a reference position pulse generator provided on the crankshaft to generate a reference position pulse indicating first and second reference positions corresponding to a predetermined crank angle; the cylinder identification signal and the reference position; A reference position signal generation circuit that generates a reference position signal and cylinder identification information corresponding to each cylinder based on a pulse, and a microcomputer that arithmetically controls the ignition timing for each cylinder based on the reference position signal and the cylinder identification information. Wherein the cylinder identification signal is a pulse corresponding to the second reference position of each cylinder and having a different pulse width only for a specific cylinder, The reference position pulse is an internal combustion engine ignition control device in which the number of pulses corresponding to the second reference position differs depending on the cylinder group.