JPH03206340A - Crank angle detecting device for internal combustion engine - Google Patents

Abstract

PURPOSE:To improve the detecting accuracy of a crank angle by fixing a rotary disk to a distributor shaft and a pickup part, consisting of at least a pair of photoelectric elements opposed to each other by interposing partly the periphery of this rotary disk, to the distributor housing. CONSTITUTION:A rotary plate 8 is mounted on the upper end part of a shaft 1, synchronously rotated with an engine, through a pair of collars 4, 6, while a printed board 12, formed with an electronic circuit, and a pickup 13 are mounted on a base 10 fixed to the bottom part of a housing 2. The pickup 13 is constituted by arranging a first to third photocouplers 13a to 13c, comprising a light emitting element 13e and a light receiving element 13f, in a predetermined angle range theta1 to detect a reference signal detecting window of the rotary plate 8 by the first photocoupler 13a and an angle signal detecting window by the second and third photocouplers 13b, 13c.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a crank angle detection device for an internal combustion engine, and in particular to a device of this type equipped with a photoelectric pickup device.

Conventionally, as shown in Japanese Unexamined Patent Publication No. 50-59632, electrical output from intermittent light received by a light receiving element is taken out directly from the housing of a power distribution device and sent to a waveform shaping circuit or an amplification circuit provided outside the power distribution device. was.

For this reason, there is a problem in that high frequency voltage due to ignition noise is likely to be superimposed on the photoelectrically converted minute voltage, resulting in poor detection accuracy.

SUMMARY OF THE INVENTION An object of the present invention is to provide a crank angle detection device for an internal combustion engine that eliminates the problems of the prior art described above and is less susceptible to the effects of high frequency voltage caused by ignition noise.

In order to achieve the above object, the present invention provides a light receiving element and a circuit for waveform shaping or amplification of the output voltage in the vicinity of the light receiving/emitting element in the power distributor housing, and generates a waveform shaped or amplified signal that is resistant to high frequency voltage noise. After converting to , this signal is output outside the power distribution device.

Furthermore, in the present invention, when the electronic circuit is built into the power distribution device, the electronic circuit is installed between the rotating disk and the bottom surface of the power distribution device housing, thereby preventing it from being exposed to high-voltage arcs from the power distribution rotor. This prevents the destruction of electronic circuit elements.

Another object of the present invention is to provide a device of this type that is easy to assemble and allows a thin rotary disk to be accurately and easily installed in a predetermined position.

In order to achieve this object, the present invention includes a rotating disk that is held between upper and lower holding members, one of these holding members is fitted and fixed to a rotating shaft, and a power distribution rotor is attached to the other holding member. It is.

According to the present invention, one holding member serves to position the photoelectric pickup, and the other holding member serves to fix the rotating disk and as a mounting member for the power distribution rotor. can be accurately fixed to the rotating shaft.

FIG. 1 is a sectional view of a power distributor that is an embodiment of the present invention.

1 is a shaft that rotates in synchronization with the engine at half the rotation speed, 2 is a housing, and 3 is a bearing.

A first collar 4 is attached to one end of the shaft, and a pin 5 is press-fitted into a flange portion 4a of this collar 4. The pin 5 fits into a hole 7 provided in the flange portion 6a of the second collar 6.

A rotary plate 8, which is one of the main features of this embodiment, is installed between the flange portions 4a and 68, and the second
The collar 6 and the first collar 4 are connected to the stepped portion 1a of the shaft 1.
The rotary plate 8 is brought into pressure contact with both the flange parts 4a and 6.
Pressure contact is made at point a.

Reference numeral 10 denotes a base, which is made of synthetic resin and is integrally molded with a connector l1 for taking out electrical signals to the outside.

A printed board 12 on which an electronic circuit is formed and a photoelectric pickup l3 are placed on the base 10, and the base 10 is fixed to the bottom of the housing 2 with screws 14.

15 is a shield plate, which picks up the wear of the side electrode 16 for high voltage power distribution, the distribution electrode 17, the center electrode 18, etc.
It is designed to prevent it from adhering to the surface.

A recess 30 a is formed in the lower part of the distribution element 30 , and a part of the shield plate 15 enters into the recess 30 a to prevent the abrasion powder from entering the space 40 .

FIG. 2 is a front view of an embodiment of the rotating plate 8. FIG.

Reference numeral 8a denotes a window for detecting an angle signal, and 360 windows are provided in the circumferential direction for each angle pitch of θ2, for example, for each degree of work.

8b is a window for detecting a reference signal, and six windows are provided in the circumferential direction at an angle pitch of θ1 of, for example, 60° in a six-cylinder engine. In order to detect the first cylinder position, one of the windows for detecting the reference signal, for example window 8bl, is made larger in the rotational direction than the other windows as shown in the figure.

Furthermore, the window is made larger on the outside of the angle θ violet, and the pitch of the edge on one side with respect to the rotation direction is set to be equal to the θ angle.

8c is a pin hole into which pin 5 in Fig. 1 is inserted.
8d is a hole into which the first collar 4 is inserted.

Figure 3 shows the main parts of Big Up 13, (a)
is a plan view, (b) is a side sectional view, and (C) is a rear view.

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. Second optical coupler 13
b and the third optical coupler 13c are 0 relative to the rotation center ○.
It is installed at an angle of 3.

The reference signal detection window 8b of the rotating plate 8 in FIG.
The angle signal detection window 8a is detected by the second optical coupler 13b and the third optical coupler 13c, respectively.

13d is a mounting hole, 13g and 13h are light emitting elements 13e
This is a hole for light passage formed between the light receiving element 13f and the light receiving element 13f. 13p is a lead wire (terminal).

FIG. 4 is a partially enlarged view illustrating the relationship between the light emitting element 13e and the light receiving element 13f of the pickup 13. The holes (slits) for light passage t3g and 13f are
It is wide enough to converge and pass light, and in the figure, the light emitting element 13e and the light receiving element 1 are connected from the slits 13g and 13f.
The tip of 3f is configured to protrude.

FIG. 5 shows another embodiment, in which the hole 1 of the pickup 13 is
3g and 13h are set large, and during assembly, the slits 13m and 13n are fixed to the entire surfaces of the respective holes 13g and 13h with adhesive or pins. Each slit 1
The intervals of 3m and 13n serve as light passing holes.

FIG. 6 is a diagram showing an example of a circuit that takes in the detection signal detected by the above-mentioned pickup I3 and realizes angle signal detection and reference signal detection. FIG. 7 shows the time chart. In FIG. 6, the circuit consists of a reference signal detection circuit RCKT and an angle signal detection circuit PCKT.

Vcc is a power supply, Rl-R12 is a resistor, and Cl and C2 are capacitors.

13a forms a first optical coupler, and light emitting element 1 3ea
, a light receiving element 13fa.

Similarly, 13b is a second optical coupler, and light emitting elements 13ed,
The optical coupler 13c in FIG. 3 consists of a light-emitting element 13ec and a light-receiving element 13fc.

The light emitting elements 13ea to 13ec use, for example, infrared light emitting diodes.

The light-receiving elements 13fa to 13fc use, for example, light-receiving diodes, and when they sense light, they generate an electromotive force between their cathodes and anodes.

The circuit operation will be explained with reference to the time chart of FIG.

Each light emitting diode 1 3ea~13ec from power supply Vcc
A current flows through the resistors Rl and R7, and the light receiving diodes 13f'a to 13c facing these are
When light is sensed, an electromotive force (positive on the anode side, negative on the cathode side) is generated between the cathode and anode.

First, the angle signal detection circuit PCKT will be explained. 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 θ2 θ3= in the relationship of the angle θ2 in FIG. It is set to be N・θ2±-2. 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.

To explain this in detail, first, the light receiving diode 13fb
When light is received, 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 O, and when the light is blocked, the voltage becomes O, and as shown in FIG.
Trying to change like this.

Similarly, in the light receiving diode 13fb, since it is connected in antiparallel to 13fB and θ3 has the above-mentioned angular relationship, a voltage that changes negatively from the reference O as shown in C in FIG. 7 will be generated. shall be.

Therefore, a voltage change, which is the sum of the voltages B and C in FIG. 7, occurs across the resistor R8 as shown in D in FIG.

On the other hand, in the reference signal detection circuit RCKT, a voltage such as A in FIG. 7 is applied to both ends of the resistor R2 at the light receiving diode 13fa of the first optical coupler 13a due to light passing through the window 8b shown in FIG. arise.

The positive input terminal of the comparator COMI has resistors R3 and R
A voltage level obtained by dividing the power supply Vcc by 4 is given, and if an input voltage higher than this level is applied to the negative input terminal, 'L' is output as the reference signal output signal REF, as shown in E in Fig. 7. Become.

The resistor R5 provides hysteresis to prevent chattering in the output signal due to minute changes in the input signal.

The positive input terminal of comparator COM2 has resistors R9 and R
A voltage level obtained by dividing the power supply Vcc with IO is given, and if the negative input terminal changes to positive or negative based on this level, as shown in F in Fig. 7 < (( L 17LL H 7+
A signal is generated as the angle signal output signal POS. The resistor Rll is for applying hysteresis as described above.

The “L” pulse width of the reference signal output REF indicated by E in FIG.
■It becomes. That is, as shown in FIG.
This is because the area of the window 8b 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 angle θ1 of the rising edge of the reference signal output REF is all the same, if the operation of the subsequent control circuit (not shown) is detected at the rising edge, the pulse width θI1 and 0
There is no problem even if 12 is different.

In order to obtain the signal for detecting the ↓ cylinder, for example, it is necessary to use the angle signal output POS shown by F in FIG.
By counting the number of in, it is easy to distinguish the cylinder from other cylinders and take it out.

In the present invention, the number of cylinders is six, but it goes without saying that any number of cylinders such as four or eight cylinders may be used.

It can also be used as a rotation angle detection device for controlling diesel engines that do not require a spark plug in the engine.

Although the window is made larger in order to detect a specific cylinder, it may be made smaller instead. Furthermore, the magnitude of θ■ may be several times larger than θ2/2. These examples depend on how the window size is set.

As explained above, according to the present invention, since the rotation pulse signal taken out from the power distributor is waveform-shaped or amplified, ignition noise is difficult to be superimposed, and even if superimposed, the rotation pulse signal and the noise can be distinguished. Since it is easy to detect, the detection accuracy is improved.

Further, since the high-voltage arc of the power distribution rotor does not fly to the electronic circuit, there is no risk that the electronic circuit will be destroyed by the high-voltage arc even though the electronic circuit is installed in the power distribution device.

According to another invention, since the rotating disk is sandwiched between the holding members and fixed to the rotating shaft, the rotating disk can be positioned accurately and easily, and
The holding member also serves as a mounting member for the power distribution rotor, improving overall assembly workability.

[Brief explanation of drawings]

Fig. 1 is a sectional view of an embodiment of the power distributor of the present invention, Fig. 2 is an embodiment of the rotating plate of the invention, and Figs. 3(a), (b), (C
) is an example diagram of the pickup, FIGS. 4 and 5 are partially enlarged examples thereof, FIG. 6 is an example diagram of the electric circuit, and FIG. 7 is a time chart. 1...Shaft, 8...Rotating plate, 13...Big up, 8a...Angle detection window, 8b, 8bl...
- Window for detecting reference position.

Claims (1)

[Claims] 1. A power distribution device housing; A shaft rotatably supported by this power distribution device housing; A power distribution rotor attached to the tip of this shaft; A power distribution rotor fixed to the shaft; and the bottom surface of the power distributor housing, and at least one pair of rotating disks facing each other across a part of the outer periphery of the rotating disk. a pickup section consisting of a light receiving and emitting element; located between the rotating disk and the bottom surface of the power distributor housing;
a photoelectric pickup unit configured of an electronic circuit electrically connected to the light receiving/emitting element, and outputting an electric pulse signal in response to an optical signal interrupted by a row of light-transmitting slits of the rotating disk; A crank angle detection device for an internal combustion engine, comprising: fixing means for fixing the photoelectric pickup unit inside the power distributor housing. 2. A crank angle detection device for an internal combustion engine as set forth in claim 1, wherein the light receiving/emitting element and the electronic circuit are integrally molded as one assembly. 3. The crank for an internal combustion engine according to claim 1 or 2, wherein the light emitting element is located above the rotating disk, and the light receiving element is located below. Angle detection device. 4. Distribution housing; A shaft rotatably supported by this distribution housing; A distribution rotor attached to the tip of this shaft; A distribution rotor fixed to the shaft, and connecting the distribution rotor and the distribution housing. a rotating disk located between the bottom surface and a ring-shaped row of transparent slits perforated at predetermined intervals; consisting of at least a pair of light receiving and emitting elements facing each other across a part of the outer periphery of the rotating disk; a pickup section, located between the rotating disk and the bottom surface of the power distributor housing,
a photoelectric pickup unit configured of an electronic circuit electrically connected to the light receiving/emitting element, and outputting an electric pulse signal in response to an optical signal interrupted by a row of light-transmitting slits of the rotating disk; A fixing means for fixing the photoelectric pickup unit inside the power distributor housing; a holding member for holding the rotating disk from both sides; and a mounting member for attaching the rotating disk to the shaft via the holding member. A crank angle detection device for an internal combustion engine, comprising: a disc mounting means comprising: