JPH06185399A - Cylinder discriminating method for internal combustion engine and rotating angle detector - Google Patents

Abstract

PURPOSE:To discriminate a reference one out of cylinders on the basis of an optical pulse which is continued or discontinued in slit trains for a rotating angle signal and cylinder judgement, disposed in a rotary disk. CONSTITUTION:A rotating angle signal pulse by a slit train 8a during a pulse width period of a pulse corresponding to a slit 8b train for a reference signal is counted in a rotating angle detector of an internal combustion engine where a crank angle is detected on the basis of an optical pulse which is continued or discontinued by the slit train 8a for rotating angle signal, formed on a rotary disk 8 to be rotated according to rotation of the internal combustion engine and a cylinder position is detected on the basis of an optical pulse which is continued or discontinued by the slit train 8b for a reference signal corresponding to cylinders of the rotary disk 8. A reference signal (slit 8b1) corresponding to a specific cylinder different in width from the other slit width is discriminated out of plural reference signals corresponding to the plurality of cylinders.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a rotation angle detecting device for an internal combustion engine, and more particularly to a rotation angle detecting device and a cylinder discriminating method suitable for discriminating a reference cylinder using a photoelectric pickup.

[0002]

2. Description of the Related Art In an internal combustion engine, in order to control ignition and fuel injection with high accuracy, it is necessary to detect a reference cylinder among the cylinders in addition to detection of a rotation angle of a crankshaft and cylinder discrimination. However, heretofore, there has been no one that detects these three simultaneously.

[0003] For example, in the prior art disclosed in Japanese Patent Laid-Open No. 50-59632, a rotating disk is fixed to a rotating shaft of a distributor, and two sets of receiving and emitting devices are installed on the front and back of the disk so as to face each other. Then, the rotation angle and the cylinder position are detected by detecting the optical signal interrupted by the slits punched in the disc. As the slits formed on the disk, two slit rows for angle detection and two cylinder rows for discriminating cylinders, which are annularly arranged on two circles having different radii, are provided. That is, in this conventional technique, the reference cylinder is not detected.

In the prior art disclosed in Japanese Patent Laid-Open No. 53-76240, a cylinder is provided with a slit array for cylinder discrimination, and a slit corresponding to the reference cylinder is provided with a hole for identifying the reference cylinder. These are detected by a pair of light receiving / light emitting devices. That is, in this conventional technique, the angle is not detected, and the angle is estimated by measuring time separately from the rotation of the disk.

In the prior art disclosed in Japanese Patent Laid-Open No. 145558/1979, the tooth corresponding to the cylinder position of the angle detecting gear of the magnetic sensor is deleted, and the deleted portion is detected,
Cylinder discrimination is being performed. In this conventional technique, the detection of the deleted portion is performed by counting the angle detection signals obtained from the non-deleted teeth to cope with the fluctuation of the rotation speed. However, similar to the above, only two types of signals are obtained, and two types of signals are detected by using two sensors.

[0006]

In each of the above-mentioned conventional techniques, only two types of signals are obtained, and the same number of sets of sensors as the number of types of signals are required. Therefore, in order to obtain the three types of signals by applying the idea of the conventional technique, three sets of sensors are required, and three rows of slits are also required on the rotating disc. This is disadvantageous in terms of space and cost, and it is more difficult to adjust the position of each slit punched on the disk than in the case of two rows.

A first object of the present invention is to make it possible to distinguish a reference signal corresponding to a specific cylinder from other reference signals based on a reference signal used for cylinder discrimination and a rotation angle signal used for angle detection. An object of the present invention is to provide a cylinder discrimination method for an internal combustion engine that simplifies the structure of the sensor.

A second object of the present invention is to make it possible to detect three kinds of signals of rotation angle position detection, cylinder discrimination, and reference cylinder discrimination from a rotating disk having two slit rows, thereby reducing the number of sensors. Moreover, it is an object of the present invention to provide a rotation angle detection device for an internal combustion engine that enables easy and reliable identification of a reference cylinder.

[0009]

The first object is to count the rotation angle signal pulses generated according to the rotation of the internal combustion engine, and to count the reference signal pulse corresponding to the cylinder of the internal combustion engine from the detection time. In the internal combustion engine rotation angle detection device for determining the rotation angle of the internal combustion engine by the count value of the rotation angle signal pulse during the pulse width period of the reference signal pulse, among the plurality of reference signals corresponding to a plurality of cylinders This is accomplished by identifying the reference signal corresponding to a particular cylinder.

The second object is to receive light from a light-emitting element intermittently provided by two rows of slits formed in an annular shape on a rotating disk that rotates in synchronization with an internal combustion engine, corresponding to the rows of slits. In the rotation angle detection device for detecting the rotation angle of the internal combustion engine by counting the number of pulse signals output from the light receiving element by the element, the rotation angle signal pulse according to the rotation of the internal combustion engine in the rotating disk. Which is a first slit array for generating a reference signal, the first slit array having a count value of the number of rotation angle signal pulses from the time when the reference signal is detected indicates the rotation angle of the internal combustion engine, and the reference corresponding to each cylinder of the internal combustion engine. The rotation angle signal during the pulse signal width period corresponding to each reference signal, in which the widths of the slits corresponding to the specific cylinders and the slits corresponding to the other cylinders are different from each other By the pulse number counting value provided a second slit rows that identifies the specific cylinder is achieved.

[0011]

According to the above cylinder discriminating method, since the width of the pulse of the reference signal corresponding to each cylinder is discriminated by the count number of the rotation angle signal and the reference cylinder among the cylinders is discriminated, the rotating disk is discriminated. Therefore, the signal detected by using the sensor is only required to be a reference signal and a rotation angle signal. Therefore, the number of sensors need only be two, and the slit array provided on the rotating disk need only be the two arrays of the slit array for the reference signal and the slit array for the rotation angle signal. All that is required is to make the slit width corresponding to the cylinder different from the other slit widths.

According to the above-mentioned rotation angle detecting device, since two rows of slits are provided on the rotating disk, two sets of sensors, which are light receiving and emitting elements for detecting optical pulses, which are intermittent in each slit row, are provided. It will be good.

[0013]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described below with reference to the drawings. FIG. 1 is a sectional view of a distributor according to an embodiment of the present invention. Reference numeral 1 is a shaft that is synchronized with the engine and rotates at half the number of rotations thereof. The first collar 4 is attached to one end of the shaft,
The pin 5 is press-fitted into the flange portion 4a of the collar 4. The pin 5 is fitted in a hole 7 provided in the flange portion 6 a of the second collar 6. A rotary plate 8, which is one of the main features in this embodiment, is mounted between the flange portions 4a and 6a, and the second collar 6 and the first collar 4 are attached by a screw 9 to the step portion 1a of the shaft 1. And press it against the rotating plate 8
Are pressed against each other at their flange portions 4a and 6a.

10 is a base, which is made of synthetic resin,
It is integrally formed with the connector 11 for taking out an electric signal to the outside. A printed board 12 having an electronic circuit formed on the base 10.
And a photoelectric pickup 13 is placed on this base
10 is fixed to the bottom of the housing 2 with screws 14. 15
Is a shield plate, a side electrode 16 for high-voltage power distribution, and a distribution electrode 1
7. The center electrode 18 is provided so that the abrasion powder and the like of the center electrode 18 does not adhere to the pickup 13. A recess 30a is formed in the lower portion of the electronic distribution 30, and a part of the shield plate 15 enters the recess 30a to prevent the abrasion powder and the like from entering the space 40.

FIG. 2 is a front view of an embodiment of the rotary plate 8. Reference numeral 8a is a window for detecting an angle signal, and 360 windows are provided in the circumferential direction at an angle pitch of θ2, for example, every 1 degree. 8
Reference numeral b is a window for detecting a reference signal, and the angle pitch of θ1 is 6
Cylinder engines are provided with six in every 60 ° in the circumferential direction. In order to detect the position of the first cylinder, one of the windows for detecting the reference signal, for example, the window 8b1 is made larger in the rotational direction than the other windows as shown in the figure. Further, the window is made larger toward the outside of the angle θ1, and the pitch of the edges on one side with respect to the rotation direction is set to be equal to θ1. 8c is a pin hole into which the pin 5 of FIG. 1 is inserted, and 8d is a hole into which the first collar 4 is inserted.

3A and 3B are views showing the main part of the pickup 13, wherein FIG. 3A is a plan view, FIG. 3B is a side sectional view, and FIG. 3C is a rear view. Reference numeral 13a forms a first optical coupler, which includes a light emitting element 13e and a light receiving element 13f. Similarly, 13b is a second optical coupler and 13c is a third optical coupler. The second optical coupler 137b and the third optical coupler 13c are installed at an angle of θ3 with the rotation center O as a reference.

The reference signal detecting window 8b of the rotary plate 8 in FIG. 2 is detected by the first optical coupler 13a, and the angle signal detecting window 8a is detected by the second optical coupler 13b and the third optical coupler 13c. Reference numeral 13d is a mounting hole, and 13g and 13h are light passage holes formed between the light emitting element 13e and the light receiving element 13f. 1
3p is a lead wire (terminal).

FIG. 4 shows a light emitting element 13e of the pickup 13,
FIG. 13 is a partially enlarged view further clarifying the relationship with the light receiving element 13f. The holes (slits) 13g and 13f for passing light have an area large enough to converge and pass the light, and in the figure, the tips of the light emitting element 13e and the light receiving element 13f project from the slits 13g and 13f.

FIG. 5 shows another embodiment of the pickup.
The holes 13g and 13h of 13 are set to be large, and the slits 13m and 13n are fixed to the entire surfaces of the holes 13g and 13h by bonding or pins during assembly. The space between the slits 13m and 13n becomes a light passage hole.

FIG. 6 is a diagram showing an example of a circuit in which the detection signal detected by the pickup 13 described above is fetched to realize the angle signal detection and the reference signal detection.

FIG. 7 shows the time chart. In FIG. 6, the circuit comprises a reference signal detection circuit RCKT and an angle signal detection circuit PCKT. Vcc is a power source, R1 to R12 are resistors, and C1 and C2 are capacitors. Reference numeral 13a forms a first optical coupler, which includes a light emitting element 13ea and a light receiving element 13fa. Similarly, 13b is a second optical coupler, which includes a light emitting element 13ed and a light receiving element 13fd, and the optical coupler 13c in FIG. 3 is a light emitting element 13e.
c, a light receiving element 13fc. The light emitting elements 13ea to 13ec use infrared light emitting diodes, for example. Light receiving element 13fa
13 to 13fc are, for example, light receiving diodes, which generate electromotive force between the cathode and the anode when light is sensed.

The circuit operation will be described with reference to the time chart of FIG. A current flows from the power supply Vcc to each of the light emitting diodes 13ea to 13ec through the resistors R1 and R7, and the light receiving diodes 13fa to 13c facing the light emitting diodes 13ea to 13ec are activated between the cathode and the anode when light is sensed. Electric power (positive on the anode side and negative on the cathode side) is generated.

First, the angle signal detection circuit PCKT will be described. The light receiving diodes 13fb to 13fc of the second optical coupler 13b and the third optical coupler 13c are connected in antiparallel, and the angle θ3 in FIG. 3 is the angle θ2 in FIG.
In this relationship, θ3 = N · θ2 ± θ2 / 2 is set. However, N is a positive integer.

Therefore, as shown in FIG. 7, a positive and negative alternating voltage as indicated by D is generated across the resistor R8. This will be described in detail. First, when light is received by the light receiving diode 13fb, a positive voltage is generated at the connection point between the resistor R8 and the negative input terminal of the comparator COM2 with the positive input terminal as the reference 0, and the light is blocked. It becomes 0, and it tries to change like B of FIG. Similarly, since the light receiving diode 13fb is connected in anti-parallel with 13fB, and θ3 has the above-described angular relationship, a voltage that changes negatively from the reference 0 as shown in C of FIG. To do. Therefore, the resistance R
A voltage change that is a combination of the voltages of B and C in FIG.

On the other hand, in the reference signal detecting circuit RCKT, the light receiving diode 13fa of the first optical coupler 13a receives a voltage such as A in FIG. 7 across the resistor R2 by the light passing through the window 8b shown in FIG. Occurs in A voltage level obtained by dividing the power supply Vcc by the resistors R3 and R4 is applied to the positive input terminal of the comparator COM1. If an input voltage higher than this level is applied to the negative input terminal, the reference signal output signal REF becomes "L". Is output and the result becomes as shown in E of FIG. Resistance R
5 is for applying hysteresis to prevent chattering in the output signal due to a slight change in the input signal.

At the positive input terminal of the comparator COM2,
A voltage level obtained by dividing the power supply Vcc is given by the resistors R9 and R10, and if the negative input terminal changes to positive or negative with reference to this level, "L" and "H" signals as shown by F in FIG. It is generated as an angle signal output signal POS. The resistor R11 is for applying hysteresis as described above.

The "L" pulse width of the reference signal output REF shown by E in FIG. 7 becomes the signal .theta.12 for detecting the first cylinder and .theta.11 for the other cylinders. That is, as shown in FIG. 2, the area of the window 8b1 is larger than that of the other windows 8b, and the output signal A of the first optical coupler is detected as a large angle. Since the angles θ1 between the rising portions of the reference signal output REF are all the same, if the operation of the control circuit (not shown) in the subsequent stage is detected at the rising portion, the pulse width θ11
There is no problem if and are different from θ12. In order to obtain the signal for detecting the first cylinder, for example, by counting the number of "1" of the angle signal output POS shown by F in FIG. Is easy.

Although the six cylinders are used in the above embodiment,
Of course, four cylinders, eight cylinders, or the like may be used. It can also be used as a rotation angle detecting device used for controlling a diesel engine that does not require an ignition plug in the engine. Further, although the window is made large to detect a specific cylinder, it may be made small. Furthermore, the magnitude of θ11 is θ
You may make it several or more larger than 2/2. These examples depend on how the window size is set.

[0029]

According to the cylinder discriminating method of the present invention, the structure of the rotating disk and the structure of the detection sensor are simplified, the manufacturing cost is reduced, and the rotation angle detecting device can be installed in a small space.

According to the rotation angle detecting device of the present invention, it is sufficient to provide only two slit rows, that is, the reference signal detecting slit row and the rotation angle signal slit row, on the rotating disc. Only two sets are required, the structure of the rotating disk and the sensor is simplified, the manufacturing cost is reduced, and it is possible to provide the device in a small space.

[Brief description of drawings]

1 is a cross-sectional view of an embodiment of a power distributor of the present invention.

FIG. 2 is a diagram showing an embodiment of a rotating plate of the present invention.

3A, 3B and 3C are a plan view, a side sectional view and a rear view of a pickup according to an embodiment.

FIG. 4 is a partially enlarged view of the pickup according to the embodiment.

FIG. 5 is a partially enlarged example view of a pickup according to an embodiment.

FIG. 6 is an embodiment diagram of an electric circuit.

FIG. 7 is a time chart.

[Explanation of symbols]

1 ... Shaft, 8 ... Rotating plate, 13 ... Pickup, 8a ...
Angle detection windows 8b, 8b ... Reference position detection windows.

Claims (2)

[Claims] 1. A rotation angle signal pulse generated according to the rotation of the internal combustion engine is counted, and a rotation angle of the internal combustion engine is obtained from a count value from a detection time point of a reference signal pulse corresponding to a cylinder of the internal combustion engine. In the rotation angle detection device,
An internal combustion engine characterized in that a reference signal corresponding to a specific cylinder among the plurality of reference signals corresponding to a plurality of cylinders is identified by the count value of the rotation angle signal pulse during the pulse width period of the reference signal pulse. Cylinder identification method. 2. A light receiving element provided corresponding to a slit row detects light from a light emitting element which is interrupted by two rows of slits formed in an annular shape on a rotating disk which rotates in synchronization with an internal combustion engine, In a rotation angle detecting device for counting the number of pulse signals output from the light receiving element to obtain a rotation angle of an internal combustion engine, a first rotation angle signal pulse is generated on the rotating disk according to the rotation of the internal combustion engine. A first slit row in which the count value of the number of rotation angle signal pulses from the detection time of the reference signal indicates the rotation angle of the internal combustion engine, and the first reference signal corresponding to each cylinder of the internal combustion engine Two
The slits corresponding to the specific cylinder and the slits corresponding to the cylinders other than the slit row have different widths, and the specific cylinder is determined by the count value of the rotation angle signal pulse number during the pulse signal width period corresponding to each reference signal. Second to identify
A rotation angle detecting device for an internal combustion engine, comprising: a slit array.