JPH01203656A - Turning angle position detecting device of rotor - Google Patents

Abstract

PURPOSE:To detect a turning position by small turning quantity by forming a plurality of portion to be detected on the second rotor rotated at the predetermined speed reduction rate to the first rotor on which a plurality of portion to be detected are formed with all the angle spaces adjacent to each other being different. CONSTITUTION:The first magnetic projections 3a through 3i are projectively provided to the first rotor 2 fixed to a crank shaft 1 with equivalent projection angle. The second magnetic projections 8a through 8d are projectively arranged on the second rotor 7 of a cam shaft 6 turning at a specified rate (2 for example) of speed reduction to the first rotor 2 with angle spaces of 60 deg., 80 deg., 100 deg., and 120 deg. respectively. The first magnetic projections 3a... and the second magnetic projections 8a... are detected by the first detection element 5 and the second detection element 10 respectively, and each of the rotary angle positions of the first rotor 2 is detected by a CPU 12 from the number of the first pulses generated from the first detection element 5 from the time of generation of the second pulse to the time of the next generation of the second pulse from the second detection element 10 and the number of the first pulses generated after that. Thus, a turning position can be detected by small quantity of turning from the start of turning.

Description

TECHNICAL FIELD The present invention relates to a device for detecting the rotational angular position of a rotating body such as a crankshaft of an internal combustion engine.

BACKGROUND ART As such a device, for example, one disclosed in Japanese Utility Model Application Laid-Open No. 61-41866 is known. In the device disclosed in the publication, a first rotating body connected to the crankshaft of a four-stroke engine and rotating together with the crankshaft is provided with a magnetic protrusion indicating a predetermined rotational angular position of the crankshaft, and the magnetic protrusion is positioned before the top dead center of the piston. The camshaft is linked to the crankshaft and rotates at 1/2 the rotation speed of the crankshaft, and a second rotating body that rotates together with the camshaft is provided to correspond to the ignition timing of the piston. A magnetic protrusion is provided as a detected part to indicate a predetermined rotational angle position before the ignition timing, and by detecting the magnetic protrusion of the second rotating body with a magnetic sensor, the crankshaft is positioned at a predetermined rotational angle position before compression top dead center. When the magnetic protrusion of the first rotating body is detected, it detects that the crankshaft has reached the rotation angle position corresponding to the ignition timing, and triggers the ignition system. That's what I do.

However, in the above configuration, if the engine is started immediately after the magnetic protrusion of the second rotating body passes a magnetic sensor that detects it, the rotational angular position of the crankshaft is detected from the beginning of rotation. The crankshaft had to turn almost two revolutions before it came off.

Therefore, the setting of the engine ignition timing was delayed, resulting in poor startability. Especially if it is a multi-cylinder engine.
Even though there is always a chance to ignite during one revolution of the crankshaft, it was not possible to ignite during that time.

SUMMARY OF THE INVENTION Therefore, in view of the above-mentioned circumstances, the present invention provides a rotational angular position detection device for a rotating body that requires a small amount of rotation of the rotating body from when the rotating body starts rotating until its rotational angular position is detected. is intended to provide.

In order to achieve the above object, in the rotational angular position detection device of a rotating body according to the present invention, a plurality of detected parts are formed at equal rotational angular intervals on the first rotating body, and a predetermined reduction ratio is established between the first rotating body and the first rotating body. A plurality of detected parts are formed on a second rotating body that rotates with a rotation speed, so that the angular intervals of adjacent detected parts are all different, and each detected part of the first and second rotating bodies is detected to detect the detected parts of the first and second rotating bodies. First and second sensing elements that emit second pulses are provided, and the first detection element is determined based on the number of first pulses generated from one second pulse generation to the next second pulse generation and the number of first pulses generated thereafter. It is characterized by detecting the rotational angular position of the rotating body.

Embodiments Hereinafter, embodiments of the present invention will be described with reference to the accompanying drawings.

FIG. 1 shows an embodiment in which a rotation angle position detection device for a rotating body according to the present invention is applied to an ignition device for a multi-cylinder four-stroke engine.

As shown in Figure 1, in this embodiment, a circular first rotating body 2 is attached to the crankshaft 1 of a six-cylinder engine (not shown), and the first rotating body 2 is attached to the crankshaft 1 along with the crankshaft 1 in the present embodiment. rotate clockwise. First rotating body 2
Nine first magnetic protrusions 3a are provided on the outer periphery of the detector as detected parts.
3b*...3h, 3i are formed at equal angular intervals in the rotation direction. A first sensing element 5 is provided near the rotation locus of the magnetic protrusion 3 and generates a first pulse every time the first magnetic protrusion 3 passes nearby. The first detection element 5 is composed of, for example, a magnetic sensor with a built-in magnetic coil, and is arranged so that the pistons of the second and fifth cylinders of the engine are at the top dead center position when the first magnetic protrusion 3a is detected. ing.

On the other hand, the rotation of the crankshaft 1 is reduced by a predetermined reduction ratio (2 in this embodiment) and transmitted to the camshaft 6 via a chain and sprocket (not shown). A circular second rotating body 7 is attached to the camshaft 6, and the second rotating body 7 rotates together with the camshaft 6 in the clockwise direction in the figure. On the outer periphery of the second rotating body, there are four second magnetic protrusions 8 a + 8 b + 8 including the detected part.
c and 8d are formed at unequal angular intervals in the rotational direction, and the angular intervals of adjacent second magnetic protrusions 8 are all different. That is, in the case of this embodiment, the angular interval between the second magnetic protrusions 8a and 8h is 60'', the angular interval between the second magnetic protrusions 8b and 8C is 80'', and the angle between the second magnetic protrusions 8C and 8d is The interval is 1000, and the angular interval between the second magnetic protrusions 8d and 8a is 120@.A second sensing element 10 similar to the first sensing element 5 is disposed near the rotation locus of the second magnetic protrusion 8. The second sensing element 10 is installed at a position where the first sensing element 5 is placed immediately after the second sensing bare hand 10 detects the second magnetic protrusion 8a while the first and second rotating bodies 2 and 7 are rotating. This is the position where the first magnetic protrusion 3a will be detected.

The first pulse emitted by the first detection element 5 when it detects the first magnetic protrusions 3a to 31 is transmitted to the amplifier 1 which also acts as a waveform shaper.
1 to the CPU 12 of the microcomputer. Further, the second sensing element 10 is connected to the second magnetic protrusions 88 to 8d.
The second pulse emitted upon detection of C
It is designed to be input to the PU12. The output level of the flip-flop 15 becomes high level due to the input to the set input terminal, and becomes low level due to the reset signal input from the CPU 12 to its reset input terminal.

In the device of this embodiment, during operation of the engine, the first pulse signal shown in FIG.
Similarly, from the second sensing element 10, the amplifier 1
3, the second pulse signal shown in FIG. 2(A) is input to the flip-flop 15.

The above-mentioned microcomputer is composed of a CPU 12, a ROM, a RAM, etc. (not shown), and performs the first rotation based on the first pulse and the output of the flip-flop 15 to which the second pulse is input, according to a program to be described later. The rotation angle position of the body 2, that is, the rotation angle position of the crankshaft 10 is detected, and when the crankshaft 1 reaches a predetermined rotation angle position, a command signal is output to an ignition unit (not shown) via amplifiers 16, 17, and 18. It is.

FIG. 3 is a flowchart showing the program. This program performs the following steps each time the first pulse described above occurs:
For example, it is executed by interrupting a main routine programmed for controlling the air-fuel ratio of the air-fuel mixture supplied to the engine.

First, when the power is turned on to the microcomputer, initialization is performed at the same time as the power is turned on, and the count values of each counter, each flag, and the flip-flop 15, which will be described later, are reset. Next, each step of the main routine described above is executed.

When the i-th pulse (see FIG. 2(B)) is input to the CPU while the main routine is being executed, the main routine is interrupted each time and the interrupt subroutine shown in FIG. 3 is executed.

When the main routine is interrupted, first, the count value CI of the crank pulse counter that counts the number of outputs of the first pulse is
is incremented (step S1), and it is determined whether the output of the flip-flop 15 is at a high level (step S2). Since the output of the flip-flop 15 is at a low level from the start of the engine until the second pulse is output for the first time, the process proceeds to step S3. It is determined whether the flag 5FEI is set (step S3). Since the flag SF is naturally not set to 1 from the time the engine starts until the second pulse is first output, the execution of the interrupt subroutine is terminated and the main routine that was being executed before the interrupt is restarted. Resume execution. Therefore, from the start of the engine until the first second pulse is output, only the operation of incrementing the count value CI of the crank pulse counter is performed.

After the engine starts, when the first second pulse is output,
The output level of the flip-flop 15 becomes high level.

Therefore, when the interrupt subroutine is executed after the output level of the flip-flop 15 becomes high level, it is determined in step S2 that the output level of the flip-flop 15 is high level, and the process proceeds to step S1, in which the flip-flop A reset signal is output to the reset input terminal of the flip-flop 15, and the output level of the flip-flop 15 is set to a low level. Next, after the first second pulse is output, it is determined whether the first pulse has already been output, in other words, whether the interrupt subroutine has already been executed once after the first second pulse has been output. , a flag IF indicating that
The determination is made by looking at the state of (step Ss). Flag IF is a flag that is set to 1 once the interrupt subroutine is executed after the output of the first second pulse, and during execution of the interrupt subroutine due to the first generation of the first pulse after the first generation of the second pulse. In step S5, the flag IF has not yet been set to 1. Therefore, the process advances to step S6, where the flag IFI::1 is set, and the count value CI of the crank pulse counter is reset to 0 (step S7). Then, the count value SC of the stage counter becomes 1. 2.4. 5. 7. Determine whether it matches any of 8 (steps 88 to 51)
3).

However, since the count value SC remains reset to zero due to initialization, it does not match any value. Therefore, the execution of the interrupt subroutine is temporarily terminated,
Return to main routine execution.

If the interrupt subroutine is executed by the occurrence of the second or subsequent first pulse after the first second pulse, the next second
Until the pulse is generated, that is, until the output level of the flip-flop 15 becomes high level due to the next generation of the second pulse, only the operations of steps 81 to S3 are repeated, and the number of times the first pulse is generated during that period is Counted by crank pulse counter. Then, when the output level of the flip-flop 15 becomes high level due to the generation of the next second pulse, the sequence proceeds from step S1→S2→S4→S5.
In step S5, it is determined whether the flag IF is set to 1 or not. Here, since the flag IF has been set to 1 in step s6 as described above, the process advances to step S14 and the flag SF is set to 1. The flag SF is a flag indicating that the second pulse after engine startup has been output twice or more, and is set to 1 when the second pulse has been generated twice or more. Next, the count value of the crank pulse counter becomes 3.4, 5.
．． Steps S+s, S16, and 817 determine whether or not they match any of the above.

S+8), if the count value CI is 3, set the stage count value SC to 1 (step 519);
If the count value CI is 4, set the stage count value SC to 5 (step 5ra), and if the count value CI is 5, set the stage count value SC to 1.
If the count value CI is 6, set the stage count value SC to 7 (step 522); if the count value CI does not match any value, proceed to step s6 and s7
Execute the action.

Now, the relationship between the count value CI and the stage count value SC will be explained. First, in this embodiment, one rotation of the crankshaft 1 is as shown in FIG.
It is composed of nine stages divided by the first magnetic protrusions 3a to 31, and each stage includes a stage starting from the top dead center of the second and fifth cylinders corresponding to the rotational reference position of the crankshaft 1. As a starting point, stage numbers 1 to 9 are assigned corresponding to each first magnetic protrusion on the front side in the rotational direction among the first magnetic protrusions that sandwich each stage. Therefore, as will be described later, the count value SC of the stage counter and the first sensing element 5 are updated every time the first pulse is generated.
By matching the actual stage number corresponding to the first magnetic protrusion 3 detected by , it is possible to know which stage the current rotational angle position of the crankshaft 1 belongs to from the stage count value SC. This is what has become. And the stage count value S
In order to match C with the actual stage number, the count value CI of the crank pulse counter is required.

As mentioned above, the count value CI counts the number of times the first pulse occurs from the first second pulse generation after the engine starts to the next second pulse generation, but as shown in Figure 1, , the second magnetic protrusion 8a after the second pulse is generated.
~8d are formed at unequal angular intervals on the outer periphery of the second rotating body, so that the first pulse is generated after the second pulse is generated by the second magnetic protrusion 8a and before the second pulse is generated by the second magnetic protrusion 8b. The number of times is 3, similarly, 4 times between the second magnetic protrusions 8b and 8C, 5 times between the second magnetic protrusions 8C and 8d, and 5 times between the second magnetic protrusions 8d and 8a. The first pulse is generated six times, and the first pulse is generated the number of times corresponding to the angular interval between the adjacent second magnetic protrusions. Therefore, as long as the first rotating body rotates at a rotation speed that is an integral multiple of that of the second rotating body, the number of times the first pulse is generated always corresponds to a specific stage. In other words, the stage number corresponding to the first pulse that occurs immediately after the generation of the second pulse of 1 is the stage number corresponding to the first pulse that occurs immediately after the generation of the second pulse of 1. It is specified by the number of pulse occurrences. Therefore, in the case of this embodiment, if the number of occurrences of the first pulse from the first second pulse occurrence to the second second pulse occurrence is three, the first pulse will occur immediately after the second second pulse occurrence. The stage number corresponding to the first pulse is 1
If the first pulse occurs 4 times, the stage number is 5, and if the first pulse occurs 5 times, the stage number is 5.
If the number of times the first pulse is generated is 6 times, the stage number is 1, and if the number of times the first pulse is generated is 6 times, the stage number is 7. The relationship between the count value CI and the stage count value SC is shown in the second diagram showing the pulse signal waveform during engine rotation.
It is shown between figures (A) and (B).

As can be understood from the above, the number of occurrences of the first pulse occurring from the first occurrence of the second pulse to the second occurrence of the second pulse is counted by a crank pulse counter, and based on the count value CI. , a value corresponding to the actual stage number corresponding to the first magnetic protrusion detected by the first detection element is set as the count value S of the stage counter.
This allows the stage count value SC to match the actual stage number.

For example, when the engine is started from position ■ in Fig. 3, the crank pulse counter counts the number of times the first pulse is generated until the second pulse PI is output, but this count value CI is By the generation of the first pulse immediately after the first second pulse P1 is output, zero reset is performed in step S7 of the above-mentioned program. Next, the first pulse that occurs before the next second pulse P2 is output.
The number of pulse occurrences is counted by a crank pulse counter. The first pulse immediately after the first second pulse PI is generated.
Since the pulse is counted as zero (zero reset), the first pulse that occurs immediately after the second pulse P2
The number of pulses is added and counted, and the count value CI is made to match the number of occurrences (5 times) of the first pulse that occurred between the second pulses P1 and 22, and the determination in steps SIS to s+8 is performed on this count value CI. Based on this determination, the stage count value SC is set to 1 in step S21, and the count value SC of the stage counter is made to match the actual stage number.

The continuation of the flowchart shown in FIG. 3 will be explained. As described above, in steps 819 to S22, the stage count value SC is set to a value corresponding to the actual stage number, and after steps S6 and S7 are executed, the determinations in steps 88 to S13 are performed. Here, if the stage count value SC is 1, an ignition command signal is issued to the ignition unit that ignites the second and fifth cylinders, and the ignition coil (
- Cut off the current to the next side) to disable ignition of the cylinder concerned (step 523), and if the stage count value SC is 2, send an energization command signal to the ignition units of the second and fifth cylinders. is emitted, and current is supplied to the ignition coil (-next side) in the ignition unit (step 524). Similarly, the stage count value SC is 4.
If the stage count value SC is 5, an ignition command signal is issued to the ignition units of the third and sixth cylinders to disable the ignition of the cylinders (step 525), and if the stage count value SC is 5, 1. L issues an energization command signal to the ignition units of the third and sixth cylinders (step 528). Furthermore, if the stage count value SC is 7, the first and fourth
An ignition command signal is issued to the ignition unit of the cylinder to disable ignition of the cylinder (step 327), and if the stage count value SC is 8, an energization command is issued to the ignition unit of the first and fourth cylinders. Issue a signal (step 52)
8). After that, it returns to the main routine execution and starts the next first routine.
When a pulse is generated, the main routine is again interrupted and the interrupt subroutine is executed.

When the main routine is interrupted again by the generation of the first pulse in this way, the process proceeds in steps S1 → S2 → S3 until the next second pulse is generated, and in step S3, the flag SF is set to 1. It is determined whether or not.

As described above, when executing the interrupt subroutine after the second second pulse is generated, the flag SF is set in step S14.
is set to 1, the determination in step S3 is YES, and the process proceeds to step S29, where the count value SC of the stage counter is incremented. Next, it is determined in step S3) whether or not the stage count value SC exceeds 9. If it is, the stage count value SC is reset to 1 (step S31).
), if it has not been exceeded, the steps from step 8 onward are executed.

In the above-described flowchart, in the unlikely event that the first sensing element 5 fails to detect the first magnetic protrusion and does not output the first pulse, the stage count value SC does not match the actual stage number. However, if the second pulse occurs twice after that, the crank pulse counter counts the number of times the first pulse occurs during that time, so the stage count value SC is determined by the first detection element based on the count value CI. It is possible to match the actual stage number corresponding to the first magnetic protrusion detected by No. 5.

As described in detail of the invention, in the rotational angular position detection device of a rotating body according to the present invention, a plurality of detected portions are formed on the first rotating body at equal rotational angular intervals, and the first rotating body and a predetermined deceleration are A plurality of detected parts are formed on a second rotating body that rotates at a ratio such that the angular intervals of adjacent detected parts are all different, and the first
and a first and second sensing element configured to detect the respective detected portions of the second concave rolling body and emit first and second pulses;
Since the rotational angular position of the first rotating body is detected from the number of first pulses generated from the second pulse generation to the next second pulse generation and the number of first pulses generated thereafter, the second The rotational angular position detection device for a rotating body is capable of detecting the rotational angular position of the first rotating body when the pulse is generated twice, and requires a small amount of rotation of the rotating body to detect the rotational angular position of the rotating body. Can be provided.

[Brief explanation of the drawing]

FIG. 1 is a block diagram of an ignition system for a 6-cylinder, 4-stroke engine to which the rotation angle position detection device of a rotating body according to the present invention is applied, and FIGS. 2(A) and (B) show the flip-flop and CPU in FIG. The second pulse input and the first pulse
The pulse signal waveform diagram in FIG. 3 is a flowchart showing the operation of the CPU in FIG. 1. Description of symbols of main parts 1...Crankshaft 2...First rotating bodies 3a, 3b, 3c, 3d, 3e, 3f, 3g. 3h, 3i...First magnetic protrusion 5...First sensing element 6...Camshaft 7...Second rotating body 8a, 8b, 8c, 8d-Old...Second magnetic protrusion 10...
...Second detection element, 12...CPU 15...Flip-flop

Claims (1)

[Claims] A first rotating body in which a plurality of detected parts are formed at equal angular intervals in the rotational direction, and a first rotating body in which the plurality of detected parts are formed so that the angular intervals of adjacent detected parts are all different in the rotational direction, and A second rotating body that rotates in conjunction with the rotating body at a predetermined reduction ratio; and a second rotating body that is provided near the rotation locus of each of the detected parts of the first rotating body and the second rotating body, so that the detected parts pass nearby. a first sensing element and a second sensing element that generate first and second pulses, respectively;
The number of the first pulses generated after the generation of the second pulse is detected and the number of the first pulses generated after that is monitored, and the rotation of the first rotating body is detected. 1. A rotational angular position detection device for a rotating body, comprising: rotational angular position detection means for detecting an angular position.