JP2513363B2 - Rotation angle sensor - Google Patents

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a rotation angle sensor used for fuel injection control and ignition timing control of an internal combustion engine, and more particularly to the shape of a rotating body in the rotation angle sensor.

[0002]

2. Description of the Related Art Conventionally, in a device for controlling fuel injection and ignition timing of an internal combustion engine, a crank angle sensor for outputting information based on determination of fuel injection timing and ignition timing, and which cylinder is used for fuel injection and ignition. Two sensors, a cylinder discrimination sensor that outputs information based on whether or not to execute it, are provided, and each control amount and control timing are set based on the information from these sensors.

In recent years, there has been proposed a device for obtaining information from the above-mentioned two types of sensors with one sensor for the purpose of cost reduction and space saving of the system (for example,
JP-A-57-137627). That is, in the pulse signal output from one sensor, this device
For example, it is determined whether the ratio of the pulse width time of the previously detected pulse signal to the pulse width time of the currently detected pulse signal is less than or equal to a predetermined value, and the pulse signal detected this time is the crank angle signal or the cylinder discrimination signal. This is what is determined by software.

[0004]

As shown in FIG. 11, the structure of the above-mentioned sensor in a four-cylinder internal combustion engine is a cylinder discriminating object for discriminating a cylinder into the rotating body 1 of a crank angle sensor which is normally used. Is provided with a protrusion 1b. Further, FIG. 12A shows the characteristic of the electric signal generated in the electromagnetic pickup 2 when the rotating body 1 rotates, and in FIG. 12, the solid line indicates the rotating body portion provided with the protrusion 1b (see FIG. 11). # 1 to # 2 are pulse signals A when passing through the electromagnetic pickup 2, and the broken line indicates the rotating body portion (# 2 in FIG. 11) where the protrusion 1b is not provided.
.About. # 3, or # 3 to # 4) is the pulse signal B when passing through the electromagnetic pickup 2.

Further, FIG. 12B shows a waveform when the pulse signals A and B are shaped into rectangular waves in the waveform shaping circuit 3, and the waveforms of the pulse signals A and B are at a predetermined level V.
When it exceeds _th , it becomes high level, and then pulse signal A,
It has a characteristic of becoming a low level when B becomes 0. That is, by using the rotating body 1 of FIG. 11, in addition to the signal indicating the predetermined crank angle, the rectangular wave has a predetermined angle,
It is possible to obtain information on the closing angle θ that holds the high level state.

Here, the problem with the conventional rotation angle sensor is that, as shown in FIG. 12 (a), the pulse signal A of the rotor portion provided with the protrusion 1b is the protrusion 1b.
The point where the pulse signal A shifts to the plus side is delayed due to the influence of, and therefore, there is also a delay at the time t when the predetermined level V _th is reached. That is, as shown in FIG. 12B, there has been a problem that only the closing angle θ ₂ of the rotating body portion provided with the protrusion 1b is reduced.

Therefore, since the ignition timing of the internal combustion engine is set based on the closing angle θ, if the closing angle θ varies in this way, the optimum ignition timing cannot be set, and the internal combustion engine is controlled accurately. There was a problem that I could not do it.

[0008] In this way, the cylinder discriminating object and the crank angle are detected.
In the rotation sensor in which the detected body and the one rotating body are provided,
The leading edge of the electrical signal corresponding to multiple crank angle detected objects
There was a problem of leading and lagging. Therefore, in view of the above problems, the present invention provides a communication system for each cylinder of an internal combustion engine.
The leading edge of the number can be obtained at a predetermined angular position without variation.
Aiming to provide a rotation sensor and its rotating body
It In particular, the present invention prevents the closing angle θ ₂ of the rotating body portion provided with the cylinder discrimination target object from becoming small, and the closing angle θ of all the cylinders is stable without variation. It is an object of the present invention to provide a device capable of obtaining the closing angle θ.

[0009]

In order to achieve the above object, the invention according to claim 1 rotates in synchronization with the rotation of an internal combustion engine, and has a plurality of objects to be detected along the circumferential direction.
And detecting the passage of each of the detected objects and
Electricity corresponding to changes in magnetic flux caused by body rotation
An electromagnetic pickup for outputting a signal,
As a body, provided on the rotating body in correspondence with the number of cylinders.
A plurality of crank angle detected objects and the crank angle detected objects
Cylinder discrimination subject to be detected that is provided at a predetermined distance behind
In the rotation angle sensor, to output the leading edge of the electric signal corresponding to the crank angle detected body at a predetermined angular position, the predetermined distance forwardly from each of the crank angle detection object
The circumferential shape of the rotating body, differently according to the distance to another of the crank angle detected body or the cylinder discrimination detection object located in front of the crank angle detected body which definitive
Technical manual of the rotation angle sensor, characterized in that a Jo
Adopt a step. It should be noted that the cylinder discrimination target object is provided only behind the predetermined crank angle target object, and the section shape between the crank angle target objects in which the cylinder discrimination target object is not formed is the rotating body. It is also possible to employ the technical means of the rotation angle sensor according to claim 1, characterized in that it comprises two ridges projecting in the same direction with respect to the rotation axis. Further, the cylinder discriminating object is provided behind the crank angle object by a predetermined distance at an interval of 1/4 to 1/9 with respect to the crank angle object. The technical means of the rotation angle sensor according to claim 1 may be adopted. Further, the cylinder discrimination subject and the crank angle subject are projected onto the rotating body, and the area of the projecting surface of the cylinder discrimination subject is larger than that of the crank angle subject. The rotation angle sensor according to claim 1 may be adopted as the technical means. In order to achieve the above object, a fifth aspect of the present invention is a rotary body for a rotation angle sensor that rotates in synchronization with the rotation of an internal combustion engine and gives a change in magnetic flux that can be detected by an electromagnetic pickup. A plurality of crank angle detection objects provided corresponding to the number and a cylinder discrimination detection object provided behind the crank angle detection object by a predetermined distance, In order to output the leading edge of the signal at a predetermined angular position , each of the cranks
Circumferential direction of the rotating body in front of the object to be detected by a predetermined distance
For a rotation angle sensor, the shape of the direction is different depending on the distance to another crank angle detected object located in front of the crank angle detected object or the cylinder discrimination detected object. The technical means of rotating body is adopted.

[0010]

According to the invention described in claim 1, one rotary member is provided.
Are the circumferential cylinder discrimination detected member along the direction of the crank angle detection object is formed, magnetic flux change corresponding to the shape of each object to be detected and the rotation of the rotating body is provided to an electromagnetic pickup, each of the cylinders , And an electric signal for cylinder discrimination are output. In this invention, the crank angle detected
The circumferential shape of the rotating body located in front of the body is important for obtaining the signal corresponding to the front edge of the crank angle detected body.
It Therefore, in order to ensure that the front edge of the signal corresponding to the crank angle detected object is obtained at the predetermined angle position, the rotation of the rotating body located a predetermined distance ahead of the crank angle detected object is detected .
The shape in the circumferential direction differs depending on the distance to another crank angle detected object located in front of the crank angle detected object or the cylinder determination detected object. For this reason, the delay and advance of the magnetic flux change due to the difference in the distance to another crank angle detected object or the cylinder discrimination detected object located in front of the crank angle detected object among a plurality of crank angle detected objects. even if, from the lag-lead crank angle detection object of the magnetic flux change
The front edge of the signal corresponding to the crank angle detected object is reliably obtained at the predetermined angular position by being compensated by the difference in the shape of the front rotating body . Further, according to the invention of claim 5 , the cylinder discriminating object and the crank angle object are formed in one rotating body, and the rotating body is in accordance with the outer peripheral shape of each of the detecting bodies and the rotating body. The magnetic flux change is given to the electromagnetic pickup. Then, in order to reliably obtain the front edge of the signal corresponding to the crank angle detected object at the predetermined angle position, the circumferential shape of the rotating body located a predetermined distance ahead of the crank angle detected object.
Is different depending on the distance to another crank angle detected object located in front of the crank angle detected object or the cylinder discrimination detected object. For this reason, the delay and advance of the magnetic flux change due to the difference in the distance to another crank angle detected object or the cylinder discrimination detected object located in front of the crank angle detected object among a plurality of crank angle detected objects. Even if there is, the delay in the magnetic flux change is ahead of the crank angle detected object
The leading edge of the signal corresponding to the crank angle detected object is reliably obtained at the predetermined angular position by being compensated by the difference in shape .

[0011]

The present invention will be described below based on the embodiments shown in the drawings. FIG. 1 is a schematic configuration diagram showing a structure of a rotation angle sensor in a four-cylinder internal combustion engine of an embodiment of the present invention.

In FIG. 1, reference numeral 1 denotes a rotating body made of a magnetic material, which rotates in synchronization with the rotation of an internal combustion engine (not shown), and more specifically makes one rotation when the crankshaft makes two rotations. It rotates in the right direction.

Further, the rotor 1 is provided with projections 1a as crank angle detection objects for detecting the crank angle of the internal combustion engine at equal intervals (90 ° in this embodiment) by the number of cylinders. ing. Further, the rotary body 1 has a protrusion 1b as a cylinder-determination detection target for determining the cylinder of the internal combustion engine, and a predetermined angle φ (in this embodiment, 1) from any one of the protrusions 1a.
5 °) One is provided at a delayed position.

In this embodiment, in order to clarify the present invention, with respect to the four protrusions 1a provided as the crank angle detection object, the protrusion 1a at a position advanced by a predetermined angle φ from the protrusion 1b will be referred to as the protrusion 1a for convenience. ₁ , the projections 1a ₂ and 1a are provided at intervals of 90 ° in the opposite direction to the rotation direction of the rotating body 1.
₃ and projection 1a ₄ .

Reference numeral 2 denotes an electromagnetic pickup, and when the rotating body 1 rotates and the projections 1a _i (i = 1 to 4) and the projections 1b pass through the electromagnetic pickup 2, a magnetic flux change occurs, and the electromagnetic pickup 2 A pulse signal P as shown in FIG. 2A is generated with the magnetic flux change as a voltage value.

Here, in FIG. 2A, the solid line is the pulse signal P by the rotating body 1 of the present invention, and the broken line is the pulse signal P by the conventional rotating body (shown in FIG. 11). Will be explained in detail later. FIG.
The waveform of (a) is the protrusion 1a _i (i = 1 to 4) and the protrusion 1
There is a characteristic that b has a maximum value (plus side) just before reaching the electromagnetic pickup 2, and the protrusion has a minimum value (minus side) immediately after passing through the electromagnetic pickup 2.

Reference numeral 3 denotes an electronic control unit 50 which will be described in detail later.
It is a waveform shaping circuit built in the inside and outputs a signal N obtained by waveform shaping the pulse signal P (FIG. 2B).
More specifically, as described above, when the pulse signal P exceeds the predetermined level V _th as shown in FIG.
After that, when the pulse signal P becomes 0, it becomes a low level signal.

Here, the feature of the present invention is that the protrusions 1a ₂ and 1a ₃ , the protrusions 1a ₃ and 1a ₄ , or the protrusions 1a ₄ and 1a ₁ are arranged at equal intervals on the rotating body 1. peripheral shape 101 to 103 is a section shape of the rotating body between, and a peripheral shape 100 is a section shape between the projection 1b and the protrusion 1a _2, as shown in FIG. 1, the projection of the crank angle detected member projecting from the projection 1a ₂ have projections 1b of the cylinder discrimination object to be detected is formed on the front as viewed from 1a ₂ 1
The outer peripheral shape 100 having a short distance to b is the outer peripheral shape 101 to between the other protrusions 1a in which the protrusion 1b is not arranged.
It is manufactured differently from 103.

This shape will be described in detail with reference to FIG. 3. In FIG. 3, the solid line shows the shape of the rotating body 1 of the present invention, the broken line shows the shape of the conventional rotating body, and the hatched portion shows the shape. It is a characteristic part of the invention and is a part newly formed to obtain the following effects.

As can be seen from this figure, the protrusion 1 of the present invention.
The outer peripheral shape of the rotating body 1 between the other protrusions 1a in which b is not provided is composed of two mountain portions (for example, 102A and 102B) protruding in the same direction with respect to the rotation axis X of the rotating body 1. . In particular, by providing the mountain portion 102A protruding in the direction opposite to that of the conventional rotating body, abrupt magnetic flux change does not occur after the projection 1a ₃ passes through the electromagnetic pickup 2. That is, as shown in FIGS. 2A and 2M, the pulse signal P does not suddenly shift from 0 to the minus side. As a result, after that, the time when the pulse signal P shifts to the positive side can be delayed, so that the time t at which the determination level V _th is reached can be delayed, and the closing angle θ (see FIG.
In (b), it is possible to control the closing angles θ ₁ , θ ₃ , θ ₄ ) to be smaller.

On the other hand, the protrusion 1a in which the protrusion 1b is provided
The outer peripheral shape 100 of the rotating body 1 in between is shown in FIG.
The protrusion 1a of the protrusion 1b₂The inflection point position on the side slope has changed
However, in more detail, the present invention is faster than the conventional inflection point (Z).
The inflection point (Y) has come to a new position. That is, the protrusion 1b
After passing through the electromagnetic pickup 2, the magnetic flux changes slowly.
The position becomes faster than before. Therefore, FIG.
As shown in (a) and (N), the pulse signal P increases from the decreasing side.
The time to move to the side becomes earlier, and then the judgment level V _thTo
The time t to reach can be shortened. This closes
Angle θ₂Can be controlled to increase.

Therefore, to make such a shape
More protrusion 1a₁, Protrusion 1a₃, And the protrusion 1a_FourIs electromagnetic
Closing angle of the corresponding signal N when passing through the pickup 2
Degree θ ₁, Closing angle θ₃, Closing angle θ_FourBecomes smaller,
Protrusion 1a₂Closing angle θ₂2 becomes larger
As shown in (b), the closing angles θ of all cylinders₁~ Θ_FourRose
It ’s possible to keep the value almost the same because there is less stickiness.
You.

In the present invention, the projection 1b is provided at a position delayed by a predetermined angle of 15 ° from the projection 1a _1. However, in general, whether the projection 1b is a crank angle signal or a cylinder discrimination signal is shown in FIG.
Since it is detected from the pulse time (T ₁ , T ₂ , T ₃ ) as shown in (b), if the predetermined angle φ is set to a large value, the engine speed Ne rapidly increases, for example, when the vehicle suddenly accelerates. In this case, the cylinder discrimination signal and the crank angle signal cannot be distinguished from each other, resulting in an erroneous determination. Therefore,
For this reason, the predetermined angle φ cannot be set to a too large value.

On the other hand, on the contrary, when the predetermined angle φ is set small (for example, 5 °), a sufficient change in magnetic flux cannot be obtained between the protrusions 1a and 1b, so that the pulse signal P is shown in FIG.
Distortion occurs as shown in, and does not rise to a predetermined level V _th . As a result, there is a possibility that a cylinder discrimination pulse does not occur when waveform shaping is performed, and cylinder discrimination cannot be performed (FIG. 4A). Therefore, for this reason, the predetermined angle φ cannot be set to a too small value.

Therefore, for the above reason, if the interval between the protrusions 1a as the crank angle detection object is C (C = 90 ° in this embodiment), the predetermined angle φ should be set to C / 4 to C / 9. Is the best in terms of cylinder discrimination accuracy.

Next, an embodiment for controlling an internal combustion engine using the above-described rotation angle sensor of the present invention will be described in detail below with reference to the drawings. FIG. 5 is a schematic configuration diagram showing a configuration of a system for controlling an internal combustion engine.

In FIG. 5, reference numeral 10 denotes the above-described rotation angle sensor, which is provided with the rotating body 1 and the electromagnetic pickup 2 of the present invention therein, and a signal from the rotation angle sensor 10 is an electronic control unit 50 described later. It is input to the waveform shaping circuit 3 inside.

Reference numeral 20 is, for example, an engine load detecting means such as an intake pipe pressure sensor for detecting a load of the internal combustion engine, 30 is a water temperature sensor for detecting a temperature such as cooling water temperature for cooling the internal combustion engine, and 40 is, for example, in the intake pipe. Other sensors for detecting the internal combustion engine state or the vehicle operating state, such as a throttle sensor for detecting the opening degree of the throttle valve. In addition,
Output signals from each of these sensors are input to the A / D conversion circuit 4 in the electronic control unit 50.

Reference numeral 50 denotes an injector, an ignition device, and other actuators for controlling the control factors of the internal combustion engine, which will be described later, for calculating the optimum control amounts of the ignition system and the fuel system based on the detection signals from the above-mentioned sensors. A known electronic control device that outputs a control signal for precise control (hereinafter,
It is called ECU).

The ECU 50 uses the above-described method to perform the waveform shaping circuit 3 for shaping the signal from the rotation angle sensor 10 into a rectangular wave, the A / D conversion circuit 4 for converting analog data into digital data, and the arithmetic processing. It is composed of a well-known microcomputer (CPU) 5 that executes.

Reference numeral 60 is an injector for supplying fuel to the internal combustion engine at an optimum timing and fuel injection amount based on the control signal from the ECU 50, and 70 is a high voltage required for spark discharge in an ignition plug of the internal combustion engine, Similarly, it is an ignition device that is generated at an optimum timing based on a control signal from the ECU 50. Reference numeral 80 denotes another actuator that controls the internal combustion engine, such as an idle speed control valve.
Also operates based on a control signal from the ECU 50.

FIG. 6 is a flow chart showing the operation when the ignition timing θ _ig is set in the ECU 50, which is a routine which is interrupted for each predetermined crank angle based on the signal from the rotation angle sensor 10.

In step 200, the engine rotation speed Ne is calculated based on the signal from the rotation angle sensor 10, and step 2
In 01, the engine load Pm is read based on the signal from the engine load detection means 20.

In step 202, the advance angle θ _AD that is the optimum ignition timing in the operating state at that time is set from the two-dimensional map of the engine rotation speed Ne and the engine load Pm, and the advance angle θ _AD is set from this advance angle θ _AD. the value representing the _AD in time (advance time) determine the T _AD.

In step 203, the time corresponding to the previous closing angle θ, that is, the time T when the waveform obtained by shaping the output pulse from the previous rotation angle sensor 10 is at a high level.
_The advance time T _AD is subtracted from _X-1 to obtain the down count value T _DC for setting the basic ignition timing.

In step 204, the down count value T _{DC is} calculated based on, for example, information from a knock sensor (not shown).
_Is corrected to set the ignition timing θ _ig , and the process returns to the main routine.

That is, this is because the point where the signal N changes from the high level to the low level is always at a predetermined crank angle (in this embodiment, every 180 ° A) in all operating conditions, and therefore, this position is generally used as a reference. Down count value T
_It asks for _DC . That is, as shown in FIG. 7, the down count value T _DC is accurately determined at the time T ₁ when the signal N becomes low level, and if the closing angle θ is the same for all cylinders, the previous closing time is set in the steady state. since not change significantly from the time T _X which corresponds to the current close angle theta between time T _X-1 corresponding to an angle theta, is that the optimum value is set by the operation described above.

However, since the closing angle θ obtained by the conventional method varies for the reason already described, the optimum ignition timing θ _ig cannot be set for all cylinders.

Therefore, by adopting the present invention, after the projection 1b passes through the electromagnetic pickup 2, the closing angle θ ₂ corresponding to the projection 1a (projection 1a ₁ ) next passing through the electromagnetic pickup 2 is changed to another closing angle. Since the closing angle θ is not smaller than θ, that is, the closing angle θ is the same for all cylinders, the time T _X-1 does not vary in the process of step 203, so the optimum down count value T _DC The excellent effect that can be set is obtained.

Next, the protrusion 1 as the detected object for cylinder discrimination.
b will be described. Although the protrusion 1b is arranged at a predetermined angle φ (15 ° in the present embodiment) behind the protrusion 1a ₁ for the above-mentioned reason, even if the protrusion 1b is provided at such an optimum position, Due to the difference between the output voltage generated by 1a and the output voltage generated by the protrusion 1b,
The characteristics are almost the same as the case shown in FIG. 4, and there is a possibility that the cylinder cannot be accurately discriminated.

This is because the projection 1b passes through the electromagnetic pickup 2 immediately after the projection 1a ₁ passes through the electromagnetic pickup 2, so that the output of the pulse signal P reaches the determination level V _th in a short time from the lowest level. This is because it will not be possible.

Therefore, in order to solve such a problem, the shape of the protrusion 1b is set as shown in FIG. Specifically, in FIG. 8, the width w ₂ of the protrusion 1b is equal to the width w _{1 of the} protrusion 1a.
The magnetic flux density when the protrusion 1b is passing through the electromagnetic pickup 2 is increased by increasing the area of the protrusion surface of the protrusion 1b. As a result, the change in magnetic flux becomes large, and the output of the pulse signal P also becomes large, so that it is possible to reliably determine the cylinder.

Further, as shown in FIG.
Similarly, the output of the pulse signal P can be increased even if the distance between the protrusion 1b and the electromagnetic pickup 2 when passing through the electromagnetic pickup 2 is made higher than a to reduce the distance.

In the above embodiment, the shape of the rotating body 1 of the rotation angle sensor that can obtain the crank angle signal and the cylinder discrimination signal with one sensor is a protrusion provided at a predetermined angle for the number of cylinders. Although the description has been given of the case where one protrusion 1b is provided as the cylinder identification detection target on 1a, it is not limited thereto, and the rotation of the rotation angle sensor for identifying the cylinder by omitting one protrusion 1b as shown in FIG. 10, for example. Body 1
The present invention may be adopted for. In this case, the protrusion 1b
The outer peripheral shape 105 of the portion in which is not provided is formed as described above.

Further, although the rotation angle sensor 10 in the four-cylinder internal combustion engine has been described in the present embodiment, the present invention may be applied to an internal combustion engine having another number of cylinders (for example, 6 cylinders).

[0046]

As described above, according to the present invention, one
It is possible to obtain the signal corresponding to each cylinder by the rotating body of
And the signal for cylinder discrimination can be obtained.
It Moreover, each crank angle is different from the one in front of the detected object.
Crank angle Distance to object to be detected or cylinder detection object to be detected
Even if the distance is different, the
Due to the different shape of the rotating body made,
Therefore, the crank angle of the electrical signal corresponding to the front edge of the detected object
Lead and lag can be compensated for, and
Be sure to obtain the leading edge of the corresponding electrical signal at the specified angular position.
Can be.

[0047]

[0048]

[Brief description of drawings]

FIG. 1 is a diagram showing a structure of a rotation angle sensor in the present invention.

FIG. 2 is a waveform diagram showing an output signal of the rotation angle sensor shown in FIG.

FIG. 3 is a diagram for explaining the shape of a rotating body in the present invention.

FIG. 4 is a waveform diagram showing an output signal of the rotation angle sensor shown in FIG.

FIG. 5 is a diagram showing the configuration of an embodiment when the present invention is applied to internal combustion engine control.

FIG. 6 is a flowchart for explaining the operation of setting the ignition timing in the device shown in FIG.

FIG. 7 is a diagram for explaining the flowchart shown in FIG.

FIG. 8 is a view showing another shape of the rotating body according to the present invention.

FIG. 9 is a diagram showing another shape of the rotating body of the present invention.

FIG. 10 is a diagram showing another shape of the rotating body in the present invention.

FIG. 11 is a diagram showing a structure and a configuration of a conventional rotation angle sensor.

12 is a waveform chart showing an output signal of the rotation angle sensor shown in FIG.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 rotary body 1a crank angle detected body 1b cylinder discrimination detected body 2 electromagnetic pickup 3 waveform shaping circuit 50 electronic control unit (ECU)

Claims (5)

(57) [Claims] 1. A rotating in synchronization with the rotation of the internal combustion engine, the circumferential direction
Along with a rotating body having a plurality of detected bodies, detecting the passage of each of the detected bodies, the rotating body
Electrical signal corresponding to the change in magnetic flux caused by rotation
And an electromagnetic pickup for outputting the object to be detected, which corresponds to the number of cylinders on the rotating body.
A plurality of crank angle detection objects provided, and a predetermined distance behind the crank angle detection objects
In a rotation angle sensor having a cylinder discriminating object, in order to output a leading edge of an electric signal corresponding to the crank angle object to a predetermined angular position , each crank angle object is detected.
In the circumferential direction of the rotating body in front of a predetermined distance from the detection body
The shape, the rotation angle sensor, characterized in that it has a different shape according to the distance to another of the crank angle detected body or the cylinder discrimination detection object located in front of the crank angle detected body. 2. The cylinder discriminant detection target is provided only behind a predetermined crank angle detection target, and the section shape between the crank angle detection target not having the cylinder discrimination detection target is formed. The rotation angle sensor according to claim 1, wherein the rotation angle sensor is composed of two ridges protruding in the same direction with respect to the rotation axis of the rotating body. 3. The cylinder discriminating object to be detected is provided at a predetermined distance behind the crank angle object to be detected at an interval of 1/4 to 1/9 with respect to the crank angle object to be detected. The rotation angle sensor according to claim 1, wherein: 4. The cylinder discriminant detection target and the crank angle detection target are projected onto the rotating body, and the area of the protruding surface of the cylinder discrimination detection target is compared with that of the crank angle detection target. The rotation angle sensor according to claim 1, wherein the cylinder discriminating object is formed so as to become larger. 5. A rotating body for a rotation angle sensor, which rotates in synchronization with rotation of an internal combustion engine and gives a change in magnetic flux detectable by an electromagnetic pickup, comprising a plurality of rotating bodies provided corresponding to the number of cylinders of the internal combustion engine. A crank angle detection target and a cylinder determination detection target provided behind the crank angle detection target by a predetermined distance are provided, and a front edge of an electric signal corresponding to the crank angle detection target is output at a predetermined angle position. to each of the crank angle to be
In the circumferential direction of the rotating body in front of a predetermined distance from the detection body
A rotating body for a rotation angle sensor, which has a different shape depending on a distance to another crank angle detected body located in front of the crank angle detected body or the cylinder discrimination detected body. .