JPH0681705A - Controller for internal combustion engine - Google Patents

Abstract

PURPOSE:To carry out an ignition control (DLI control) without using a distributor and provide a high cylinder determining ability even at the starting by a 3-sensor system comprising a rotation pulse sensor (CYL sensor) which gives 1 pulse against the burning process of the whole cylinders, a rotation pulse sensor (TDC sensor) which gives 1 pulse per burning process of one cylinder, and a rotation pulse sensor (CRANK sensor) which gives 1 pulse per a specific crank angle. CONSTITUTION:An output waveform of a TDC sensor 5 is shaped in a control part 6. The sorts of the TDC pulse width, which are obtained by waveform shaping, and their order are predetermined by the constitution of teeth 3 for long pulses and teeth 4 for short, pulses, which are provided to the circumference part of an iron gear 2. When the order of these pulses width is divided by every certain number of cylinders, the patterns showing the order of these pulses width are limited in a certain number, so that the cylinder is specified at a less rotational angle of a crank shaft by applying these patterns to each of the cylinders respectively beforehand.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a cylinder discrimination of an engine control device of an internal combustion engine using a rotation pulse sensor, and a rotation pulse sensor (CYL sensor) of 1 pulse for the combustion stroke of all cylinders of the engine, Rotation pulse sensor (TDC sensor) with 1 pulse per combustion stroke of 1 cylinder
And a rotation pulse sensor (CRANK sensor) for each specific crank angle (30 °, 36 °, 45 °, etc.).

[0002]

2. Description of the Related Art Conventional three sensors (CYL sensor / TDC
10 to 12 for a cylinder discrimination system using a sensor and a CRANK sensor, taking a 6-cylinder internal combustion engine as an example.
Will be described with reference to.

FIG. 10 shows a first conventional example, in which a cycle of generating a CYL pulse by a rotation pulse sensor (CYL sensor) of 1 pulse for the combustion stroke of all cylinders of the engine is two revolutions of the engine ( The combustion cycle of all cylinders is 760 °) and TD corresponding to this CYL pulse
The cylinder is identified by the C pulse. In this case, two engine revolutions were required in the worst case to identify the cylinder when the engine was started. Therefore, to improve startability,
At the time of starting, fuel injection is performed in all cylinders simultaneously to overcome this drawback.

FIG. 11 shows a second conventional example, which is a method of enhancing the starting performance by preparing two CYL sensors and arranging them at 360 ° intervals. In recent years, engine control by ignition control without a distributor (hereinafter referred to as DLI) has been performed. In this case, however, since it is not possible to ignite all cylinders at the same time, the problem of poor startability with the three-sensor system occurs. Therefore, two CYL sensors are used to improve startability.

FIG. 12 shows a third conventional example, in which the cylinders on the opposite side of the crankshaft angle of 360 ° are simultaneously ignited (the opposite cylinder is the exhaust stroke after the explosion, so there is no problem in igniting). ) Method.

[0006]

However, in the above first example, there is a problem that the cylinder cannot be discriminated at the time of starting, and in the above second example, when two CYL sensors are used, the sensor is not detected. There is a problem that a total of four sensors are required for the alternative control in consideration of the failure of the above. Further, in the third example, when the opposite cylinders are simultaneously ignited, the burden on the igniter is doubled. Therefore, there is a problem that the characteristics of DLI cannot be fully utilized.

The present invention solves the above-mentioned conventional problems and involves three sensors (CYL sensor, TDC sensor,
It is an object of the present invention to provide an excellent internal combustion engine control device that can realize DlI control by a CRANK sensor system and can realize a high cylinder discriminating ability even at the time of starting.

[0008]

SUMMARY OF THE INVENTION In order to achieve the above object, the present invention relates to a combustion stroke of all cylinders of an engine.
Pulse rotation pulse sensor (CYL sensor) and 1 pulse rotation pulse sensor (TD for one cylinder combustion stroke)
C sensor) and specific crank angle (30 °, 36 °, 45
Rotation pulse sensor (CRANK sensor) for each degree, etc. is provided to shape the output waveform of the TDC sensor,
The CRANK pulse includes information on an edge serving as a reference for a specific crank angle and information on at least two types of pulse widths that enable the cylinder to be specified.

[0009]

The present invention has the above-described structure, and the order of the types of pulse widths obtained by shaping the output waveform of the TDC sensor is a predetermined order of repetition. When divided by the number of cylinders of, the pattern showing the order of the pulse width is limited to some, and by applying these patterns to each cylinder in advance, at a smaller crankshaft rotation angle. The cylinder can be specified.

[0010]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described below with reference to the drawings. FIG. 1 shows a control device for an internal combustion engine according to an embodiment of the present invention. In FIG. 1, reference numeral 1 denotes a cam shaft, which is supported so as to rotate at a rotation speed that is ½ of that of a crank shaft (not shown). Reference numeral 2 is an iron gear fixed to the cam shaft 1, and a tooth 3 for long pulse is provided on the circumference thereof.
And teeth 4 for short pulses are formed. Reference numeral 5 denotes a TDC sensor, which outputs an electric waveform by the electromagnetic induction effect of the magnetic pickup coil when the long pulse tooth 3 and the short pulse tooth 4 pass near the gap. Reference numeral 6 denotes a control unit, which performs control such as cylinder discrimination according to the output waveform of the TDC sensor 5.

Although not shown in FIG. 1, two other iron gears are coaxially fixed to the camshaft 1, and each of them has a structure similar to that of the TDC sensor 5. A CYL sensor and a CRANK sensor are provided.
The outputs of these sensors are sent to the control unit 6.

FIG. 2 is an enlarged view of the tooth 3 for long pulse and the tooth 4 for short pulse. In FIG. 2, the reference A is the iron gear 2.
4 shows a reference position when the circumference of the circle is equally divided into predetermined angles corresponding to the number of cylinders of the engine. The long pulse tooth 3 has a smaller inclination angle at the rising portion than the short pulse tooth 4.

FIG. 3 shows the output waveform of the TDC sensor 5 and the waveform shaping in the control section 6. 3A shows the output waveform of the TDC sensor 5 for the long pulse tooth 3, and FIG. 3B shows the output waveform of the TDC sensor 5 for the short pulse tooth 4. By comparing these output waveforms with a predetermined threshold value in a comparator inside the control unit 6, the TDC of long pulse and short pulse as shown in FIGS. 3C and 3D is obtained. The pulse can be obtained. Here, the falling edge positions of the long pulse and the short pulse are respectively synchronized with the reference position when the circumferential portion of the iron gear 2 is equally divided into a predetermined angle corresponding to the number of cylinders of the engine. However, it is a rotation pulse for each specific crank angle (30 °, 36 °, 45 °, etc.) C
The reference position for the RANK pulse does not change due to the difference in pulse width.

In this way, as shown in FIG. 1, when the camshaft 1 rotates in the direction of the arrow in response to the rotation of the crankshaft, a predetermined timing is shown in FIGS. 3 (c) and 3 (d). The long pulse and the short pulse as shown are sequentially generated according to the arrangement of the long pulse tooth 3 and the short pulse tooth 4 provided on the circumferential portion of the iron gear 2. Regarding the CYL sensor and CRANK sensor, the CYL pulse and CRA as in the first conventional example shown in FIG. 10 are provided by an iron gear (not shown) provided coaxially with the iron gear 2 shown in FIG.
Pulses similar to the NK pulse are generated, and these pulses are shaped by the controller 6 in the same manner as the TDC sensor 5.

Next, a method for identifying the cylinder position from the order of generation of the long pulse and the short pulse of the TDC pulse will be described.

FIG. 4 shows the TDC pulse generation state of the internal combustion engine for 6 cylinders. The order of pulse width is "long
“Long, short, long, short, short” are repeated. When the pulse width order is divided into three cylinders, the pulse width order is limited to the following six types of patterns. "Long / Long / Short""Long / Short / Long""Short / Long / Short""Long / Short /
Short, “short, short, long” “short, long, long.” These 6
The type pattern is applied to each cylinder in advance.
In FIG. 4, # 1 to # 6 represent cylinder numbers.
In this way, the cylinders can be specified by detecting the TDC pulse widths for three cylinders.

FIG. 5 shows the TDC pulse generation state of a four-cylinder internal combustion engine. The order of pulse width is "long
When the pulse width order is divided into two cylinders, the pulse width order is limited to the following four types of patterns. ”
"Long / Short""Short / Short""Short / Long" These four types of patterns are applied to each cylinder in advance. In FIG. 5, # 1 to # 4 represent cylinder numbers. In this way, the cylinder can be specified by detecting the TDC pulse width for two cylinders.

6 and 7 show TDC pulse generation states of the 5-cylinder and 8-cylinder internal combustion engines. In the case of FIG. 6, four types of pulse widths are shown. In these cases as well, similar to the case of the internal combustion engine for 6 cylinders, by detecting the TDC pulse widths of 3 cylinders, patterns of 5 types and 8 types are applied to each cylinder in advance. Can be specified.

4 to 7, the cylinder is specified by using only the TDC pulse, whereas the cylinder shown in FIG.
The one shown in (1) specifies the cylinder by using the TDC pulse and the CYL pulse together. In the case of the 6-cylinder internal combustion engine, the cylinders can be specified earlier than in the case of FIG. 4 by detecting the pulse width of 2 cylinders. That is, in FIG. 8, the order of the TDC pulse width is the same as that in the case of FIG. 4, and “long / long / short / long.
It is a repetition of "short and short". And, the CYL pulse is placed between the TDC pulses.
When the pulse width order is divided into two cylinders, the combination pattern of the TDC pulse width order and the presence or absence of the CYL pulse sandwiched between the TDC pulses is the following six types of patterns. That is, if there is a CYL pulse, "Yes"
If there is no CYL pulse, and there is no, the combination pattern is “long / absent / long” “long / present / short” “short /
Yes / Long “Long / No / Short” “Short / No / Short” “Short / No / Long”
Becomes These six types of patterns are applied to each cylinder in advance. As described above, in the case of FIG. 4, the cylinder can be specified by detecting the TDC pulse widths of three cylinders, whereas in the case of FIG.
By using the pulse together, the cylinder can be specified by detecting the TDC pulse width for two cylinders.

By making the width of the long pulse more than twice the width of the short pulse in the above embodiment, the discrimination in the comparator inside the control unit 6 becomes more stable. Further, in the above embodiment, the cylinder is specified by the two types of TDC pulse widths of the long pulse and the short pulse. However, in order to generate three or more types of TDC pulse width, By configuring the teeth, it is possible to specify the cylinder earlier (smaller rotation angle of the cam shaft 1).
(For example, in a four-cylinder internal combustion engine, four types of T
If the configuration is such that a DC pulse is generated, it is possible to specify the cylinder for each cylinder. Further, in the above embodiment, a magnetic pickup coil type sensor utilizing an electromagnetic induction effect is used, but an optical pickup type or a Hall element type may be considered. FIG. 9 shows the case of the Hall element method. In this case, the width of the output pulse can be changed by changing the width of the teeth formed on the circumferential portion of the iron gear 2.

[0021]

According to the present invention, as is apparent from the above-described embodiment, the order of the types of pulse widths obtained by shaping the output waveform of the TDC sensor is a predetermined order of repetition. When the order is divided into several cylinders, the patterns indicating the order of the pulse width are limited to several patterns. By applying these patterns to each cylinder in advance, the following patterns are obtained. It has an effect. 1) At the time of starting, since the cylinder position can be specified with a smaller rotation angle of the crankshaft, the startability of the engine can be greatly improved. 2) Since the cylinder position can always be confirmed by detecting the pulse width even after the engine is started, even if a cylinder error occurs due to external noise, it can be quickly corrected and the toughness of the engine can be improved. 3) 3 sensors (CYL sensor, TDC sensor, CRAN)
Even if an abnormality occurs in any one of the K sensors), the remaining two sensors can perform alternative control for identifying the cylinder position. 4) Even in ignition control using a distributor that is not the DLI system, the cylinder position can be specified with the same configuration as the DLI system, so that the design can be shared.

[Brief description of drawings]

FIG. 1 is a configuration diagram of a control device for an internal combustion engine according to an embodiment of the present invention.

FIG. 2 is a side view of a tooth for TDC pulse in the same embodiment.

FIG. 3 is an output waveform diagram of the TDC sensor and its waveform shaping diagram in the same embodiment.

FIG. 4 is a diagram showing a TD of a 6-cylinder internal combustion engine in the embodiment.
C pulse generation state diagram

FIG. 5: TD of a four-cylinder internal combustion engine in the same embodiment
C pulse generation state diagram

FIG. 6 is a TD of a 5-cylinder internal combustion engine according to the same embodiment.
C pulse generation state diagram

FIG. 7: TD of an 8-cylinder internal combustion engine in the same embodiment
C pulse generation state diagram

FIG. 8 is a generation state diagram of CYL pulses and TDC pulses in the same embodiment.

FIG. 9 is a configuration diagram of a control device for an internal combustion engine according to another embodiment.

FIG. 10 is a sensor output waveform diagram of a conventional internal combustion engine control device.

FIG. 11 is a sensor output waveform diagram of another conventional control apparatus for an internal combustion engine.

FIG. 12 is a state diagram showing simultaneous ignition of a control device for another conventional internal combustion engine.

[Explanation of symbols]

 1 Camshaft 2 Iron Gear 3 Tooth for Long Pulse 4 Tooth for Short Pulse 5 TDC Sensor 6 Controller

─────────────────────────────────────────────────── ─── Continuation of the front page (51) Int.Cl. ⁵ Identification code Internal reference number FI technical display area F02P 7/067 302 C

Claims (4)

[Claims] 1. The combustion stroke of all cylinders of the engine is 1
Pulse rotation pulse sensor (CYL sensor) and 1 pulse rotation pulse sensor (TD for one cylinder combustion stroke)
C sensor) and specific crank angle (30 °, 36 °, 45
(CRANK sensor) for each rotation pulse sensor (CRANK sensor) for each internal combustion engine control device.
An internal-combustion-engine control device comprising: information on an edge serving as a reference of a specific crank angle of a pulse; and information on at least two types of pulse widths capable of specifying a cylinder. 2. The control device for an internal combustion engine according to claim 1, wherein the control device has two types of pulse widths, long and short, capable of discriminating the waveform of the TDC sensor. 3. The control device for an internal combustion engine according to claim 2, wherein the width of the long pulse is at least twice the width of the short pulse. 4. The control device for an internal combustion engine according to claim 2, wherein the signal of the CYL sensor is arranged between the pulses of the TDC sensor.