JPH1019915A - Device for determining abnormality in magnetic protrusion - Google Patents

Abstract

PROBLEM TO BE SOLVED: To obtain a device for determining abnormalities in magnetic protrusions capable of reducing work and labor in a miniaturized size with lowered cost. SOLUTION: This device is for determining abnormalities in a plurality of magnetic protrusions provided on a mobile body and equipped with a galvano- magnetic device 15 arranged opposite to the magnetic protrusions and an abnormality determining means 42 for determining abnormalities in the magnetic protrusions on the basis of electric signals VE from the galvano-magnetic device. The galvano-magnetic device 15 converts the changes in gap with the magnetic protrusions to electric signals according to magnetic flux and produces an output. The abnormality determining means 42 contains a computing means 43 which computes a determination value γ on the basis of the peak value deviation of the electric signals and a comparison determining means 44 for comparing the determination value with an abnormality determining standard.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for judging an abnormality of a magnetic projection, which is determined by electrical means, for example, for determining a defect of a magnetic projection disposed on a signal detecting plate or the like driven in synchronization with the rotation of an internal combustion engine. The present invention relates to an apparatus, and more particularly to an apparatus for judging abnormality of a magnetic projection, which has reduced work labor, and has been reduced in size and cost.

[0002]

2. Description of the Related Art In general, a magnetic projection provided on a moving body such as a signal detection plate which rotates integrally with an engine is provided with:
Since it is used for detecting the angle and position of a moving object, accuracy and reliability are required. Therefore, it has been conventionally checked before the actual use that there is no abnormal height or missing of the magnetic projection.

FIG. 12 is a block diagram schematically showing a conventional magnetic judging portion abnormality judging device. Here, a signal detecting plate (ring gear) corresponding to engine rotation is shown.
The case where the abnormality of the upper magnetic protrusion is determined is shown.

FIG. 13 is an enlarged side view showing a signal detection plate provided on the crankshaft of the engine 1 together with each detector, and FIG. 14 is an enlarged sectional view showing the rotation detector in FIG. 15 is a plan view of only the connector portion of the rotation detector in FIG. 14 viewed from below, and FIG. 16 is a circuit diagram showing a specific configuration example of a waveform shaping circuit in the rotation detector. In the drawings, the same or corresponding portions are denoted by the same reference numerals and description thereof will be omitted.

In FIGS. 12 and 13, the internal combustion engine, that is, the engine 1 has a signal detecting plate 50 (see FIG. 13) which is synchronously driven integrally with the crankshaft. The signal detection plate 50 is made of a magnetic material, and has a plurality of magnetic projections 51 and a recess 52 between the magnetic projections 51 along the outer periphery. Each magnetic protrusion 51
They are arranged at predetermined angular intervals and have the same tooth height h, tooth width w, and tooth gap p, respectively.

A normal signal detection plate 50 has, for example, a diameter φ of 302 mm and a plate thickness of 2 mm, and has a diameter of 1 mm on its outer periphery.
It has 80 magnetic projections 51. The magnetic projection 51 and the recess 52 are formed at equal intervals, and the magnetic projection 51 has a tooth width w of about 2 mm and a tooth height h of about 3 mm.

A rotation detector 10 comprising a magnetic sensor (for example, an electromagnetic pickup) is provided with a signal detecting plate 5.
0, and outputs a rotation angle signal Rθ corresponding to the magnetic projection 51.

[0008] The rotation angle signal Rθ is input to a microcomputer 31 having various arithmetic functions and timekeeping functions, and is used for controlling the engine 1. The microcomputer 31 also receives other various detection signals (not shown) such as a cylinder discrimination signal and a reference position signal.

A non-contact type displacement detector, for example, a laser displacement meter 18 is disposed opposite to the signal detection plate 50 similarly to the rotation detector 10, and outputs a gap detection signal DE for determining abnormality of the magnetic projection 51. Output. Output converter 40
Captures the gap detection signal DE from the laser displacement meter 18 and outputs a displacement signal ΔDE indicating the gap displacement between the magnetic projection 51 and the magnetic projection 51. The determination device 41 calculates the displacement signal ΔD
The defect and abnormality of the magnetic projection 51 are determined based on E.

Referring to FIGS. 14 and 15, a rotation detector 10 includes a core 2 constituting a magnetic path, a magnet 3 disposed on an axis of the core 2 and magnetized in the axial direction of the core 2, and a magnet 3. A spacer 4 arranged on the axis of 3 to form a magnetic path;
A coil 70 wound on the core 2 via the bobbin 5,
A cylindrical guide portion 6 integrally formed with the bobbin 5,
A waveform shaping circuit 9 for processing the rotation angle signal Rθ into a rectangular wave signal composed of a voltage pulse, and a terminal 10 for external connection
a to 10c are integrated.

The magnet 3 and the spacer 4 are inserted and fixed in the guide portion 6. Further, a coil wire 71 serving as an input / output terminal of the coil 70 is wound and locked around a terminal 81 provided at one end of the guide portion 6, and forms a primary molded product integral with the bobbin 5 and the guide portion 6. ing. Note that the other end of the terminal 81 is also provided at other plural places (not shown).

A primary molded product integrally formed with the bobbin 5 and the guide portion 6 is fixed together with the terminals 10a to 10c to a molding die (not shown), and the outside thereof is secondarily molded to form a casing. 20 and 3 pole connector part 2
1 is formed. The material for secondary molding is made of the same or equivalent synthetic resin material as the bobbin 6, for example, PBT (polybutylene terephthalate), PP (polypropylene), nylon, or the like.

Waveform shaping circuit 9 arranged on secondary molded product
Is the other end of the terminal 81 on the primary molded product (not shown)
Terminal 1 via a ribbon lead 91 made of, for example, an Fe-Ni alloy.
0a to 10c are electrically connected.

The ribbon lead 91 is electrically connected to the waveform shaping circuit 9 by, for example, welding. Also,
The upper surface of the waveform shaping circuit 9 is covered with a cover 25 fixed to the secondary molded product, and forms a rotation detector 10 (magnetic sensor) in which the waveform shaping circuit 9 is integrated.

The terminal 10a functions as an output terminal for supplying the rotation angle signal Rθ converted into a rectangular wave signal by the waveform shaping circuit 9 to the microcomputer 31, and the terminal 10b functions to shape an external power supply (not shown). Circuit 9
Functions as a power terminal connected to the terminal 10c.
Functions as a ground terminal for connecting the ground to the waveform shaping circuit 9. The connector 2 of the rotation detector 10
The arrangement of the terminals 10a to 10c in FIG.
The order is not limited to that shown in FIG.

With the above-described connection configuration, the voltage signal Vd generated by the coil 70 is input to the waveform shaping circuit 9 via the other end of the terminal 81, and becomes a rectangular wave rotation angle signal Rθ by the waveform shaping circuit 9, and the terminal 10a Is supplied to the microcomputer 31 via the.

In FIG. 16, a waveform shaping circuit 9 includes a filter connected to a coil 70 and a reference voltage generating circuit 1.
3, a comparator 14 connected to the output terminal of the reference voltage generation circuit 13, and a power supply circuit 91 connected to an external power supply via the terminal 10b. Each circuit in the waveform shaping circuit 9 is formed on a single substrate.

The filter and reference voltage generating circuit 13
Terminals 81a and 8 which are the other ends of terminal 81
1b is connected to the coil 70 to remove the noise superimposed on the voltage signal Vd from the coil 70, to output the final voltage detection signal VD, and to be a reference serving as a comparison reference for pulse conversion in the comparator 14. It outputs a voltage signal VR.

The comparator 14 compares the voltage detection signal VD with the reference voltage signal VR, and outputs a rotation angle signal Rθ composed of a rectangular pulse. After stabilizing the power supply voltage supplied from the terminal 10b, the power supply circuit 91 supplies the stabilized power supply voltage to the filter and reference voltage generation circuit 13 and the comparator 14, respectively.

Next, the operation of a general rotation detector 10 in which the waveform shaping circuit 9 is integrated will be described with reference to FIGS. 12 to 16, taking the case where the rotation detector 10 is a magnetic sensor as an example. The rotation detector 10 is arranged via a predetermined gap (air gap) G with respect to a signal detection plate 50 (see FIG. 13) interlocked with the crankshaft of the engine 1.

When the signal detection plate 50 is rotated by driving the engine 1, the magnetic projection 51 formed on the circumference of the signal detection plate 50 and the rotation detector 10 disposed opposite to the magnetic projection 51 are rotated. The distance to the core 2 varies periodically. For example, the distance G corresponding to the gap between the magnetic projection 51 and the core 2 is shortest when the magnetic projection 51 is opposed to the core 2 and is longest when the magnetic projection 51 is opposed to the recess 52.

The magnet 3 in the rotation detector 10 has, for example, an N pole on the side facing the magnetic projection 51 and an S pole on the other side.
The magnetic flux generated from the magnet 3 is magnetized to be a pole.
It passes through a core 2 and a spacer 4 forming a magnetic path. Therefore, the amount of magnetic flux passing through the core 2 changes according to the displacement of the magnetic projection 51 serving as an object to be detected, that is, the displacement of the air gap G. I do.

That is, the rotation of the signal detection plate 50 causes the magnetic resistance between the signal detection plate 50 and the magnet 3 to periodically fluctuate in accordance with the magnetic projections 51, causing a change in magnetic flux. I do. At this time, a voltage e corresponding to a change in the amount of magnetic flux Φ is output to both ends of the coil 70 by the following relational expression.

E = -n (dΦ / dt)

In the above equation, n is the number of turns of the coil 70. As a result, in the positional relationship between the magnetic projection 51 on the signal detection plate 50 and the magnet 3 in the rotation detector 10, from the time when the two start to shift to the state in which they are opposed to each other, the time when the transition to the state in which they do not end is completed. Since a change in the magnetic flux occurs, the rotation detector 10 outputs a voltage-converted rotation angle signal Rθ.

FIG. 17 is a waveform diagram for explaining the operation of the waveform shaping circuit 9 in the rotation detector 10. The relationship between the plate shape of the signal detection plate 50, the voltage detection signal VD and the rotation angle signal Rθ is shown. Is shown.

In FIG. 17, the voltage detection signal VD is an output voltage waveform based on the voltage signal Vd from the positive terminal of the coil 70, and oscillates substantially symmetrically around the reference voltage VG, for example. The rotation angle signal Rθ is obtained by slicing the voltage detection signal VD with another reference voltage VR (> VG) and converting it into a rectangular wave signal.

In this case, when the magnet 3 starts to face the magnetic projection 51 on the signal detection plate 50, the voltage detection signal VD is maximized on the positive electrode side because the magnetic flux change dΦ / dt is in a maximum increase state. Conversely, when the magnet 3 starts to face the concave portion 52 on the signal detection plate 50, the magnetic flux variation dΦ / dt is in a state of maximum decrease, so that the maximum value is obtained on the negative electrode side.

The comparator 14 in the waveform shaping circuit 9
The voltage detection signal VD is changed to a reference voltage VR at a slice level.
And performs waveform shaping processing on the zero cross point a1 from the positive electrode side to the negative electrode side and the zero cross point a2 from the negative electrode side to the positive electrode side of the voltage detection signal VD, and outputs a rotation angle signal Rθ formed of a rectangular wave.

As described above, when the magnetic projection 51 of the signal detection plate 50 faces the rotation detector 10, the voltage detection signal VD serving as a positive electrode signal is obtained. , A rectangular rotation angle signal Rθ subjected to waveform shaping processing is obtained.

On the other hand, similarly to the rotation detector 10, the laser displacement gauge 18 arranged opposite to the signal detection plate 50 has the magnetic projection 51 on the signal detection plate 50 rotating in synchronization with the engine 1 approaching. Every time, the absolute position of the magnetic projection 51 is output as the gap detection signal DE.

The output converter 40 converts the gap detection signal DE into a displacement signal ΔDE, and the judging device 41 compares the displacement signal ΔDE with a preset storage value (permissible range) and outputs a signal detection signal. The quality of the height from the rotation center of 50 to the magnetic protrusion 51 is determined.

The microcomputer 31 captures not only the rotation angle signal Rθ from the rotation detector 10 but also operating state information from various other sensors (not shown) (for example, a throttle opening sensor, a temperature sensor). A predetermined calculation process such as an ignition timing for the engine 1 is performed, and the engine 1 is controlled based on the calculation result.

FIG. 18 is an enlarged waveform diagram showing a rectangular pulse shape of the rotation angle signal Rθ input to the microcomputer 31. FIG. 18A shows a low-speed rotation (idle rotation of about 600 rpm), and FIG. Is high rotation (about 7500 rpm
The waveform at time m) is shown.

The microcomputer 31 includes, for example,
The rotation angle signal Rθ at the time of low rotation shown in FIG. 18A is compared with the high slice level HSL and the low slice level LSL, and each slice section T1, T2, T3,.
, The duty ratio (T1 / (T1 + T2), T
2 / (T2 + T3),... Further, the microcomputer 31 counts the pulses of the measured rotation angle signal Rθ, and uses the counted pulses together with the various sensor signals described above for predetermined calculation and control.

Usually, a capacitor (not shown) for preventing surge noise is provided between the signal output terminal 10a of the waveform shaping circuit 9 (see FIG. 16) and the ground terminal 10c. The rotation angle signal Rθ obtained based on the magnetic protrusions 51 and the recesses 52 of the signal detection plate 50 has a rising edge that becomes slower as the engine speed increases.

Therefore, the duty ratio measured by the microcomputer 31 due to the influence of the above-described capacitor is equal to the rotation angle signal Rθ at the time of high rotation shown in FIG.
, As the engine 1 speed increases, T1
Is small (large for T2).

However, since the microcomputer 31 performs the digital sampling process, there is a limit in the recognizable duty ratio.
When SL is 4 V and the low slice level LSL is 1 V, only the duty ratio within the range of 50% ± 25% can be recognized.

Therefore, if the duty ratio deviates from the range of 50% ± 25% at the time of high rotation when the rising edge of the rotation angle signal Rθ becomes slow (see FIG. 18B), measurement becomes impossible.

Next, the effect on the rotation angle signal Rθ when an abnormality occurs in the magnetic projection 51 on the signal detection plate 50 will be described. FIGS. 19 and 20 are waveform diagrams showing the voltage signal Vd and the rotation angle signal Rθ when the magnetic projection 51e having an abnormal tooth height he (<h) is present, and FIG. 19 shows the step Δh of the magnetic projection 51e. (= Hh
When e) is large, FIG. 20 shows the case where the step Δh is small.

In each figure, (a) shows a rotation angle signal R at low rotation (minimum starting rotation speed of about 40 rpm).
θ and (b) show the rotation angle signal Rθ at the time of high rotation (maximum rotation number of about 7500 rpm). Voltage signal Vd
Is composed of the positive signal Vp and the negative signal Vn from the coil 70, and the positive signal Vp near the magnetic protrusion 51e.
Pe1 and Vpe2, and the negative polarity signals Vne1 and Vne2 increase or decrease with respect to the normal amplitude.

Now, as shown in FIG. 19, the magnetic projections 5 having a constant pitch and a constant tooth height h on the signal detection plate 50.
It is assumed that a magnetic projection 51e having an abnormal tooth height he is present in 1. At this time, the abnormal magnetic projection 51e
A step Δh (= h−he) is formed between the normal magnetic protrusion 51 and the normal magnetic protrusion 51 (for example, the magnetic protrusion immediately before the rotation direction of the signal detection plate 50).

In general, dents on the signal detection plate 50,
Bends and scratches are collectively referred to as abnormalities.
From the viewpoint, the one that suddenly changes the relative distance (that is, the gap G) to the magnetic protrusion 51 corresponds to an abnormality. FIG.
9, the step Δh in the magnetic protrusion 51e is different from the magnetic protrusion 51 of the signal detection plate 50 and the rotation detector 10e.
Since the relative distance to is rapidly changed, it will be described below as a typical example of the abnormality.

In FIG. 19, in the vicinity of the magnetic projection 51e having the step Δh, the relative distance to the rotation detector 10 sharply increases, and the amount of interlinkage magnetic flux of the coil 70 sharply decreases. Therefore, the rotation detector 10 is connected to the magnetic protrusion 51
e, the magnetic projection 51e
, The amplitude of the negative signal Vne1 becomes larger on the negative side than the normal negative signal Vn.

Subsequently, the rotation detector 10 is connected to the magnetic projection 51.
e, the amplitude of the positive signal Vpe1 is smaller than that of the positive signal Vp for the normal magnetic projection 51 because the decrease in the relative distance is reduced and the change in the amount of magnetic flux interlinking the coil 70 becomes slow. Become.

The rotation detector 10 has a magnetic projection 51e.
Signal Vne2 when facing the concave portion 52 immediately after
Since the increase in the relative distance is reduced and the change in the amount of magnetic flux interlinking the coil 70 becomes slow, the amplitude becomes smaller than that of the normal negative signal Vn.

Further, the positive signal Vpe2 when facing the magnetic protrusion 51 immediately after the magnetic protrusion 51e, the relative distance decreases substantially sharply, and the amount of magnetic flux interlinking the coil 70 sharply increases. Therefore, the amplitude is larger than the positive signal Vp for the normal magnetic projection 51. Hereinafter, the positive / negative signal of the voltage signal Vd for the normal magnetic projection 51 has constant amplitudes Vp and Vn corresponding to the constant tooth height h.

At this time, as shown in FIG.
Since the positive signal Vpe1 for 1e does not reach the reference voltage (slice level) VR, a pulse missing portion Rθe occurs in the rotation angle signal Rθ. The pulse missing portion Rθe occurs at the time of low rotation as shown in FIG. 19A and at the time of high rotation as shown in FIG. 19B.
This may cause an error in the measurement of the number of pulses in the microcomputer 31 and cause erroneous control.

For example, if the diameter of the signal detection plate 50 is 302 mm, the plate thickness is 2 mm, the tooth width w of the magnetic projection 51 is 2 mm, and the tooth height h is 3 mm, as described above, as shown in FIG. As shown in FIG.
The lower limit value of the step Δh that causes the pulse missing portion Rθe of θ is:
For example, it is about 0.2 mm. Therefore, the step Δh
Exceeds 0.2 mm, a pulse missing portion Rθe occurs.

On the other hand, as shown in FIG. 20, when the step Δh between the abnormal magnetic projection 51e and the normal magnetic projection 51 is smaller than that in FIG. 19, the voltage signal Vd near the magnetic projection 51e is reduced. Positive signals Vpe1 and Vpe2 of
In addition, the amount of change between the negative signals Vne1 and Vne2 and the normal positive signal Vp and negative signal Vn is reduced.

In the case of FIG. 20, since the positive signal Vpe1 for the magnetic projection 51e exceeds the reference voltage VR, the number of pulses of the rotation angle signal Rθ that has been waveform-shaped by the reference voltage VR can be obtained normally.

However, since the amplitude of the positive signal Vpe1 is smaller than the normal positive signal Vp, in the processing in the microcomputer 31, the high-side slice level HSL
The detection position (see FIG. 18) is shifted in a time-delayed direction. Therefore, the microcomputer 31
The duty ratio measured within the normal magnetic projection 51
It becomes smaller than the case.

In particular, at the time of high rotation as shown in FIG. 20 (b), the rise of the rotation angle signal Rθ becomes slow due to the influence of the above-mentioned noise preventing capacitor, and the detection position at the slice level HSL is temporally changed. 20A, the duty ratio becomes even smaller than at the time of low rotation in FIG.

As described above, since the duty ratio of the rotation angle signal Rθ corresponding to the magnetic projection 51 decreases as the engine speed increases, for example, the duty ratio for the magnetic projection 51e having the step Δh is low. In some cases, the value may be reduced to a value that cannot be recognized at a high rotation speed, even if recognized by the microcomputer 31 during rotation.

Conventionally, the function test of the magnetic projections 51 on the signal detection plate 50 has been executed while being driven at a constant rotation in a line process before assembly. The rotation is set relatively low in consideration of the above. In such an engine assembly line, not only the already installed rotation detector 10 for engine control but also another detector for detecting the state (for example, tooth height h) of the magnetic projection 51, that is, a laser displacement meter. 18 are needed.

When the signal detection plate 50 is driven at a constant rotation speed on the assembly line, the judging device 41 determines the magnetic projection based on the variation signal ΔDE of the air gap detection signal DE obtained from the laser displacement meter 18. 51 is determined.

Although the rotation detector 10 in which the waveform shaping circuit 9 is integrated is used here, the waveform shaping circuit 9 and the rotation detector 10 may be separated. Further, although the laser displacement meter 18 is used as a detector for checking the tooth height h of the magnetic protrusion 51, a mechanical displacement meter such as a dial gauge 55 may be used as shown in FIG.

In FIG. 21, an operator (not shown)
Before the signal detection plate 50 is assembled to the engine 1, the dial gauge 55 is pressed against the magnetic protrusion 51 and the concave portion 52 to directly measure the height thereof, and the height of the magnetic protrusion 51 is measured.
Is determined.

In this case, the work of judging the abnormality of the magnetic projection 51 is performed before the signal detection plate 50 is assembled to the engine 1, and the height of the magnetic projection 51 and the recess 52 is measured to obtain a predetermined size. After confirming that it is within the range, the operation shifts to the work of delivering the signal detection plate 50.

However, even if the signal detection plate 50 has a dent, a bend, a flaw, or the like on the assembling line, assembling work, or the like during the transportation, it is difficult to perform the inspection again immediately before assembling. This is because various devices are densely arranged around the assembled engine 1 and there is no room for disposing the dial gauge 55 and the like.

As described above, in the assembling work and the confirmation test work of the engine 1, the engine speed is reduced to the idle speed (about 600 rpm to 1000 rpm) for the purpose of ensuring the safety of the worker and maintaining the environment. Must be set.

However, the duty ratio of the rotation angle signal Rθ decreases as the engine speed increases, and further decreases in the case of the magnetic protrusion 51e having the step Δh. During rotation, it is not possible to detect a lack of output of the rotation angle signal Rθ or a missing pulse due to an inability to determine the duty ratio.

If the signal detection plate 50 is to be checked after the signal detection plate 50 is assembled to the engine 1, the signal detection plate 50 is
It is necessary to check the state of the magnetic projections 51 arranged on the outer periphery of this, which is practically almost impossible.

As described above, if the laser displacement meter 18 (see FIG. 12) dedicated to determining the quality of the magnetic projection 51 is provided together with the rotation detector 10 that outputs the rotation angle signal Rθ for engine control, Can be checked, but an expensive laser displacement gauge 18 is required, which leads to an increase in cost.

Further, the laser displacement meter 18 needs to be disposed to face the signal detection plate 50 with high accuracy, and the relative distance from the magnetic protrusion 51 needs to be set short in order to improve the detection accuracy. And the installation work and adjustment are very difficult. Furthermore, it is necessary to provide a dedicated hole for attaching the laser displacement meter 18 to the engine 1, which leads to a structural increase in cost around the engine 1 where there is little room.

[0066]

As described above, the conventional apparatus for determining an abnormality of a magnetic projection uses the dial gauge 55, so that the measurement accuracy cannot be obtained. Therefore, the reliability of the abnormality determination is low. There has been a problem that it is not possible to make an abnormality determination in a state after assembly.

When the laser displacement gauge 18 is used, it is necessary to dispose it with high accuracy and a short distance relative to the magnetic projection 51, and the mounting structure is restricted. There has been a problem that mounting work and adjustment become difficult, which leads to an increase in cost.

The present invention has been made in order to solve the above problems, and has as its object to provide a magnetic protrusion abnormality judging device which can reduce the working labor and realize a reduction in size and cost. .

[0069]

According to a first aspect of the present invention, there is provided an apparatus for determining abnormality of a magnetic projection provided on a moving body, the apparatus comprising: a magnetic projection; A magnetic-electric converter disposed opposite to the portion, and abnormality determining means for determining abnormality of the magnetic protrusion based on an electric signal from the magnetic-electric converter. Is converted into an electric signal corresponding to the change in magnetic flux and output, the abnormality determining means is a calculating means for calculating a determination value based on a peak value deviation of the electric signal, and a comparison determining means for comparing the determination value with an abnormality determination reference. Is included.

According to a second aspect of the present invention, there is provided an apparatus for judging abnormality of a magnetic projection portion according to the first aspect, wherein:
An average value calculating means for calculating an average value of the peak values of the electric signal, and a correction coefficient calculating means for calculating a correction coefficient based on the average value, wherein at least the correction value is used to correct the peak value deviation to determine the determination value. It is assumed that.

According to a third aspect of the present invention, in the magnetic judging device for judging abnormality of the magnetic projection according to the second aspect, the average value calculation means uses the sample number m of the electric signal to be latched to obtain the peak value V. average of (i) VAVG a (i), is calculated by _{VAVG (i) = Σ n =} i-m + 1 i V (n) / m, the correction coefficient calculating means, the average value VAVG
Using the lower limit value VAVG (i) low of (i) and the constants a and b, the correction coefficient α (i) is calculated as the average value VA
When VG (i) is equal to or larger than the lower limit value VAVGlow, α (i) = a × {VAVG (i) −VAVGlow}
+ B, and the average value VAVG (i) is equal to the lower limit value VAVG.
When the peak value is smaller than low, α (i) = 1 is set, and the calculating means uses the peak value V (i) to calculate the peak value deviation ΔV.
(I) is calculated by ΔV (i) = V (i) −V (i + 1), and the determination value γ (i) corrected using the average value VAVG (i) and the correction coefficient α (i) is calculated as follows: γ (i) = α (i) × ΔV (i) / VAVG (i) × 1
The comparison determination means determines the abnormality of the magnetic projection when the determination value γ (i) exceeds a predetermined threshold value.

According to a fourth aspect of the present invention, there is provided the magnetic judging device abnormality judging device, wherein the comparing and judging means compares the judging value γ (i) with a single threshold value.

According to a fifth aspect of the present invention, there is provided an apparatus for determining abnormality of a magnetic projection according to the first aspect, wherein the movable body is a rotating plate, and the magnetoelectric converter comprises: a coil wound around the core; An electromagnetic pickup includes a magnet disposed on an axis and the electric signal is a voltage signal output from the electromagnetic pickup.

According to a sixth aspect of the present invention, there is provided an apparatus for judging abnormality of a magnetic projection according to the fifth aspect, wherein the moving body is a signal detecting plate connected to the engine, and the magnetoelectric converter is a signal detecting plate. A rotation detector disposed opposite to the magnetic projection formed on the plate, the rotation detector includes a waveform shaping circuit that outputs a rotation angle signal corresponding to the rotation of the engine, and the electric signal is a waveform shaping circuit. It is obtained by branching a voltage signal input to the circuit.

According to a seventh aspect of the present invention, in the magnetic judging portion abnormality judging device according to the sixth aspect, the electric signal output terminals are integrated into a connector having a rotation angle signal output terminal. It was done.

[0076]

BEST MODE FOR CARRYING OUT THE INVENTION

Embodiment 1 FIG. FIG. 1 is a block diagram showing Embodiment 1 of the present invention, and shows a case where the moving body is a signal detection plate 50 as in the above. FIG. 2 is an enlarged side view showing the signal detection plate 50 together with each detector.
In each of the drawings, the same or corresponding portions as those described above (FIGS. 12 and 13) are denoted by the same reference numerals and description thereof is omitted.

The magnetoelectric converter 15 for abnormality detection (for example,
The magnetic sensor) is a signal detection plate 50 (see FIG. 2).
And converts the change of the air gap G between the magnetic projection 51 and the concave portion 52 into an electric signal VE corresponding to a change in magnetic flux, and outputs the electric signal VE.

In this case, the magnetoelectric converter 15 is disposed ahead of the rotation detector 10 by a distance corresponding to a predetermined angle with respect to the rotation direction (arrow R) of the signal detection plate 50. Therefore, the electric signal VE from the magnetoelectric converter 15 is output at a timing earlier than the rotation angle signal Rθ from the rotation detector 10 by a time corresponding to the predetermined angle amount.

The abnormality determining means 42 for determining the abnormality of the magnetic projection 51 based on the electric signal VE is composed of a microcomputer, and comprises a calculating device 43 for calculating a judgment value γ based on the peak value deviation of the electric signal VE; A comparison / determination device 44 that determines abnormality of the magnetic protrusion 51 based on the determination value γ.

The abnormality judging means 42 has a peak hold circuit (not shown) at the input part, and latches the electric signal VE output from the magneto-electric converter 15 by the peak hold circuit, and then sends the signal to the arithmetic unit 43. To be entered.

The arithmetic unit 43 calculates an average value VAVG of the peak values VAVG of the electric signal VE, and an average value VVG.
Correction coefficient calculating means for calculating the correction coefficient α based on the AVG, and outputs a judgment value γ obtained by correcting the peak value deviation using at least the correction coefficient α.

The comparing and judging device 44 includes a memory means in which a threshold value (allowable upper limit) γ TH serving as an abnormality judging reference is stored in advance, and a comparing and judging means for comparing the judgment value γ based on the peak value deviation with the threshold value γ TH. And determination means for determining the quality of the magnetic protrusion 51 based on the comparison result.

Next, the arithmetic processing operation of the arithmetic unit 43 in the abnormality determining means 42 will be described with reference to the waveform diagram of the electric signal VE (FIG. 3). The waveform of the electric signal VE in FIG. 3 shows a case where the signal detection plate 50 has an abnormal magnetic projection 51e, as in the above (see FIG. 19).

In FIG. 3, an electric signal VE obtained at each timing i corresponds to each magnetic projection 51 provided on the signal detection plate 50, and a step Δh (FIG.
The change of the electric signal VE (i-1) corresponding to the magnetic projection 51e having the same as described above is as described above.

The arithmetic unit 43 in the abnormality determining means 42 obtains a determination value γ for abnormality determination based on the electric signal VE. Here, first, the peak value deviation Γ before performing the correction operation using the correction coefficient α. The calculation process (i) will be described.
The arithmetic unit 43 converts the electric signal VE into the following (1)
The peak value deviation Γ (i) before the correction is obtained by performing the calculation of Expressions (4) to (4).

First, the peak value Va of the electric signal VE in the positive direction is obtained.
Using the sum of (i) and the peak value Vb (i) in the negative direction, the peak value Vpp (i) corresponding to each step of the magnetic protrusion 51.
Is calculated by the following equation (1).

Vpp (i) = | Va (i) | + | Vb (i) | (1)

The peak value V in the positive direction at each timing
The deviation ΔVa (i) of a (i) is calculated by the following equation (2).

ΔVa (i) = Va (i) −Va (i + 1) (2)

The average value V of the peak values Vpp (i-m + 1) to Vpp (i) of the past m electric signals including the i-th electric signal VE (i) corresponding to the magnetic projection 51e.
ppAVG (i) is calculated by n = im + 1, im,.
The sum is calculated by the following equation (3) obtained by dividing the sum of −1 and i by m.

VppAVG (i) = ΣVpp (n) / m (3)

In the equation (3), m is the abnormality determination means 42
Is the number of samples of the electrical signal VE latched within Subsequently, the peak value deviation ΔVa in the positive direction obtained from the equation (2)
(I) and average value VppAVG obtained from equation (3)
The peak value deviation Γ (i), which is a ratio with respect to (i), is calculated by the following equation (4).

Γ (i) = ΔVa (i) / VppAVG (i) × 100 [%] (4)

In the above equations (1) to (4), Vpp (i) in the equation (1) is, for example, the amplitude between the positive and negative peaks of the i-th electric signal VE (i) corresponding to the magnetic projection 51e, that is, the wave. High values are shown. In addition, ΔVa in equation (2)
(I) is a forward peak value Va of the electric signal VE (i).
(I) and the forward peak value V of the next electric signal VE (i + 1)
The peak value deviation from a (i + 1) is shown.

VppAVG (i) in equation (3) is
The average value of the peak values of the m electric signals before the i-th electric signal VE (i) is shown, and Γ (i) in equation (4) is the average amplitude value VppAVG ( The ratio of the peak value deviation ΔVa (i) to i) is shown.

The arithmetic unit 43 corrects the peak value deviation Γ (i) corresponding to the rate of change by the correction coefficient α (i), as described later, and outputs the corrected determination value γ (i) for signal detection. The calculation is performed for all the magnetic projections 51 on the plate 50.

On the other hand, the comparison / determination device 44 in the abnormality determination means 42 determines the maximum value γmax of the determination values γ (i), which is the final calculation result of the arithmetic device 43, and the threshold value γTH stored in advance. Are compared, and the quality of the magnetic projection 51 provided on the signal detection plate 50 is determined based on the comparison result.

Here, the calculation result before the correction by the calculation device 43, that is, the peak value deviation Γ (i) will be specifically described. The signal detection plate 50 to be determined is made of an iron-based magnetic material, for example, SPCC (cold rolled steel plate).
As described above, it is assumed that the diameter is 302 mm, the thickness is 2 mm, and 180 magnetic projections 51 and recesses 52 are formed at equal intervals on the outer periphery.

The tooth width w of the magnetic projection 51 is 2 mm,
The tooth height h is 3 mm, and the core 3 of the rotation detector 10 (FIG. 1)
4) and the magnetic projection 51 have a gap G of 0.3 mm to
It is set within a range of about 1.5 mm. Engine 1
Is about 800 rpm (75
It is driven at a rotation speed of 0 to 850 rpm, and the rotation speed variation at this time is about ± 50 rpm.

The upper limit value of the step Δh allowed for the magnetic protrusion 51 (set to the side where the tooth height h is lower than the normal tooth height position) is 0.2 mm, and the step Δh is less than 0.2 mm. It is assumed that the magnetic projection 51 is regarded as normal. However, even if the step Δh is less than the upper limit (0.2 mm),
If five or more consecutive magnetic protrusions 51 just below the upper limit are detected consecutively, it is regarded as abnormal, and the quality is determined based on the comparison result within the five consecutive teeth.

Table 1 is a table showing actually measured data values for determining the threshold value γTH to be compared with the maximum judgment value Γmax (deviation before correction).
The relationship between the maximum determination value Δmax [%] with respect to each rotation speed [rpm] and each gap G [mm] when m is set is shown.

Table 1 750 rpm 800 rpm 850 rpm 0.3 mm 15.7% 15.7% 15.6% 0.7 mm 16.7% 17.4% 16.8% 1.1 mm 19.7% 19.6% 19 0.7% 1.5mm 23.6% 22.4% 23.2%

Table 2 shows that the step Δh of the five consecutive teeth is 0.
In the case where the maximum determination value Γmax is measured in the case of 2 mm, each rotation speed [rpm] and each gap G [m
m] to the average value VppAVG [V] of the electric signal VE.
Shows the relationship.

Table 2 750 rpm 800 rpm 850 rpm 0.3 mm 6.10 V 6.36 V 6.61 V 0.7 mm 2.28 V 2.41 V 2.50 V 1.1 mm 1.07 V 0.80 V 0.82 V 1.5 mm 0.55 V 0.58V 0.60V

From Table 1, it can be seen that the determination value Δmax [%] increases as the gap G increases. Also,
Although not shown here, it is known that the determination value Γmax generally becomes larger than the values in Table 1 as the step Δh increases. On the other hand, from Table 2, as the air gap G increases, the average value V of the amplitude of the electric signal VE increases.
It turns out that ppAVG [V] becomes small.

Now, the threshold value γTH stored in advance in the comparing and judging device 44 in the abnormality judging means 42 is equal to the gap G
It is assumed that the value is constant irrespective of the magnitude of the step Δh. In this case, from Table 1, for example, the rotation speed is 750 rpm
It is necessary to set the pass / fail judgment criterion, that is, the threshold value γTH, so that m is substantially equal to the judgment value Γmax (= 23.6%) corresponding to the maximum gap G (= 1.5 mm).

As described above, the fixed threshold value γTH ({23.
6), if the gap G is a relatively small value within the allowable range, for example, about 0.7 mm, the determination value Γmax is about 16.7%, and the step Δh is the allowable value (0.2 mm). Despite the above, the judgment value Γm
ax may not be equal to or greater than the threshold value γTH.

Therefore, even though the signal detection plate 50 is defective, the judgment value Δmax is equal to the threshold value γT.
H, and the comparison determination device 44 in the abnormality determination means 42 may erroneously determine “normal”.

As described above, since the judgment value Γmax and the average value VppAVG (i) change depending on the gap G, it is understood that it is necessary to correct the above equation (4). Therefore, the arithmetic unit 43 calculates the determination value γ (i) corrected by the following equation (5) in consideration of the change of the average value VppAVG due to the change of the gap G.

Γ (i) = α (i) × ΔV (i) / VppAVG (i) × 100 [%] (5)

However, in the equation (5), α (i) is a correction coefficient for compensating the variation of the gap G, and as will be described later,
It is calculated using the average value VppAVG (i) of the amplitude of the electric signal VE.

Next, the process of calculating the correction coefficient α (i) will be specifically described. Generally, the maximum judgment value γmax of the judgment values γ (i) and the average value V
The relationship with ppAVG (i) is as shown in FIG. 4 from Tables 1 and 2 above.

In FIG. 4, a square dot represents a gap deviation Δ
G (corresponding to step Δh) = 0.29 mm magnetic projection 51
If there is only one tooth, the diamond dot is the gap deviation Δ
When there is only one magnetic protrusion 51 of G = 0.22 mm, the triangular dot has a gap deviation ΔG = 5 when there are five continuous magnetic protrusions 51 of 0.2 mm, and the round dot has a gap deviation ΔG = It is plot data in the case where there is only one tooth of the magnetic protrusion 51 of 0.17 mm.

Each of the hatched dots has a rotation speed of 850 r.
pm, each white dot is plot data when the rotation speed is 800 rpm, and each black dot is plot data when the rotation speed is 750 rpm. From FIG. 4, the determination value γmax and the average value VppA
It can be seen that VG exhibits almost constant characteristics irrespective of fluctuations in the rotational speed, and that the judgment value γmax decreases as the average value VppAVG (i) increases and increases as the gap deviation ΔG increases.

Therefore, the correction coefficient α (i) is
As a function of ppAVG (i), the average value VppAVG
Regardless of (i), if the maximum determination value γmax is made to approach a constant value, the following equation (6) is satisfied as a failure determination condition of the signal detection plate 50.

Γmax> γTH (6)

As an example, the average value VppA in all target conditions (gap G, rotation speed, step Δh)
Using the lower limit value VppAVGlow of VG (i) and the constants a and b, the correction coefficient α (i) is set by the following equation (7).

Α (i) = a × {VppAVG (i) −VppAVGlow} + b (7)

However, equation (7) is an arithmetic equation when the relationship between VppAVG (i) and the lower limit value VppAVGlow satisfies the following condition.

VppAVG (i) ≧ VppAVGlow

If VppAVG (i) and the lower limit Vpp
When the relationship with AVGlow satisfies the following conditions,
α (i) = 1 is set.

VppAVG (i) <VppAVGlow

Note that the lower limit value VppAVGlow, the constant a
And b, the number of samples m, and the threshold value γTH are set according to the characteristics of the magnetoelectric converter 15, the shape and rotation speed (moving speed) of the signal detection plate 50 (moving body), and variations in the gap G. .

By performing a correction operation using the above equations (5) and (7), the characteristic shown in FIG.
The correction is made as shown in the characteristic diagram of FIG. That is, it is understood that the characteristic is such that the variation of the determination value γ with respect to the gap G is suppressed, and the quality of the test object can be clearly determined based on the determination value γ regardless of the variation of the gap G.

Therefore, if the correction result of FIG. 5 is determined by using the equation (6), the quality of the signal detection plate 50 can be accurately determined. At this time, it is assumed that each constant (the number of samples m, the average value VppAVG (i), a, b, and the threshold γTH) is set, for example, as in the following equations (8) to (12).

M = 3 (8) VppAVGlow = 0.40 [V] (9) a = 0.178 (10) b = 1.100 (11) γTH = 22 [%] (12)

Further, a step Δh of less than 0.2 mm is allowed, and the step Δh is allowed continuously within 5 teeth. As is clear from FIG. 5, the threshold value γTH (= 2
2 [%]) is determined as a defective product when the determination value γ of not less than 0.2 [%] is calculated, regardless of the variation of the gap G.
It can be seen that the signal detection plate 50 having the magnetic protrusion 51e having a step Δh of 2 mm can be reliably determined to be defective.

In the first embodiment, the lower limit value of the average value VppAVGlow, the number of samples m, a and b
Is set as in the equations (8) to (11), but the present invention is not limited to this.

For example, as described above, the characteristics of the engine 1 having the signal detection plate 50 to be measured, the shape of the signal detection plate 50, the gap G to be set, the sensor characteristics of the magnetoelectric converter 15, and the characteristic confirmation Engine speed,
The maximum judgment value γma is determined by the difference between the allowable value of the step Δh and the like.
Needless to say, x, the average value VppAVG of the amplitude of the electric signal VE changes.

Therefore, the above constants and expressions are set in accordance with the output characteristics of average value VppAVG of electric signal VE. When the threshold value γTH for the determination value γ is set to 22% and the step Δh which is equal to or greater than the allowable value (= 0.2 mm) is determined to be defective, the constant given by the above equations (8) to (11) is as follows: To (16).

M = 3 to 10 (13) VppAVGlow = 0.20 to 2.50 [V] (14) a = 0.150 to 0.190 (15) b = 0.500 to 1.500 … (16)

As described above, the equation (7) for obtaining the correction coefficient α (i) varies depending on the shape of the signal detection plate 50, the characteristics of the magnetoelectric converter 15, and the like. Thereby, it is possible to reliably determine the abnormality of the magnetic projection 51 without adjustment and to realize a cost reduction.

That is, the arithmetic unit 43 performs an arithmetic operation using a mathematical expression determined by a predetermined constant, and compares the determination value γ, which is the arithmetic result, with a threshold value γTH set in advance by the comparison and determination unit 44 to obtain a signal. The quality of the detection plate 50 can be easily and inexpensively determined.

At this time, even if the output characteristic of the electric signal VE from the magnetoelectric converter 15 has a characteristic that depends on the gap G, the above equation is corrected by the correction coefficient α (i). When γ is compared with the threshold γTH, the quality of the signal detection plate 50 can be reliably determined.

In the first embodiment, the magneto-electric converter 15 is a magnetic sensor. However, any device may be used as long as it generates an electric signal VE in accordance with the shape of the signal detection plate 50 and the gap G. Although the amplitude between the positive and negative peak values of the electric signal VE is used as the peak value Vpp (i), any peak value V (i) such as Va (i) or Vb
One of (i) may be used.

Embodiment 2 Further, in the first embodiment, the magnetoelectric converter 15 different from the rotation detector 10 is used in order to obtain the electric signal VE for abnormality detection, but the rotation angle signal Rθ from the rotation detector 10 is divided. Then, it may be used as the electric signal VE.

FIG. 6 shows a second embodiment of the present invention in which the rotation angle signal Rθ from the rotation detector 10 is shared with the electric signal VE.
FIG. 3 is a block diagram showing the same or corresponding parts as in FIG.

FIG. 7 is an enlarged sectional view showing the peripheral structure of the rotation detector 10 in FIG. 6, and FIG. 8 is a plan view of the rotation detector 10 in FIG. 14 and 15) are assigned the same reference numerals and explanations thereof will be omitted.

FIG. 9 is a circuit diagram showing a specific example of the configuration of the waveform shaping circuit 9 in FIG. 7, and the same or corresponding parts as those described above (FIG. 16) are assigned the same reference numerals and described. Is omitted.

In this case, the rotation detector 10 is connected to the abnormality determining means 42 via the two-pole connector 22.
Not only the rotation angle signal Rθ for the microcomputer 31 but also the electric signal VE for the abnormality determination means 42 are supplied. Note that the microcomputer 31 includes the time measuring device as described above.

In the rotation detector 10 shown in FIGS. 7 to 9, terminals 81c and 81d at both ends of the coil 70 are provided.
Are externally exposed as a positive electrode terminal and a negative electrode terminal, and supply a voltage signal Vd generated from the coil 70 to the outside as an electric signal VE via the connector 22.

The lead wire 85a is connected to the terminal 81c serving as a positive terminal by, for example, solder, and the lead wire 85b is electrically connected to the terminal 81d serving as the negative terminal, for example, by solder. Also, the lead wires 85a and 85
b are connected to the terminals 1 in the connector 22, respectively.
2a and 12b and the connector 22
The connector 22 is configured to supply an electric signal VE to the outside.

The flange 45 provided integrally with the rotation detector 10 has a bush 46 and is positioned and fixed to the engine 1 to maintain the facing relationship with the signal detection plate 50. The flange 45 is integrally formed with the bush 46 at the time of secondary molding of the rotation detector 10.

In FIG. 9, the positive terminal 81 of the coil 70
The voltage signal Vd output from c is supplied to the waveform shaping circuit 9 via the terminal 81a, and is supplied to the abnormality determining means 42 as an electric signal VE via the lead wire 85a and the terminal 12a of the connector 22. Is done.

Similarly, the negative (ground) terminal 81d of the coil 70 is connected to the waveform shaping circuit 9 via the terminal 81b.
And connected to the abnormality determining means 42 via the lead wire 85b and the terminal 12b of the connector 22.

As shown in FIG. 9, by using a rotation detector 10 integrated with a waveform shaping circuit 9 as a magnetoelectric converter, an electric signal V for determining abnormality of the signal detection plate 50 can be obtained.
Since E is obtained, the aforementioned magnetoelectric converter 15 (see FIG. 1)
Becomes unnecessary, and further downsizing and cost reduction can be realized.

Further, by sharing the rotation detector 10 for generating the rotation angle signal Rθ with the magnetoelectric converter 15 for abnormality detection, only one mounting hole is provided in the engine 1 and further simplification is realized. I do.

Embodiment 3 FIG. In the second embodiment, the negative electrode (ground) terminal of the coil 70 is connected to the lead wire 85 b and the connector 2 using the two-pole connector 22.
Although the second terminal 12b is connected to the abnormality determining means 42 via the second terminal 12b, the ground terminal 10c of the waveform shaping circuit 9 may be shared with the negative terminal of the coil 70, and the connector 22 may be omitted.

In this case, the connector 2 of the rotation detector 10
By using 1 as a four-pole configuration, the function of the connector 22 is integrated with the rotation detector 10, and the size can be further reduced.

FIG. 10 shows the ground terminal 1 of the waveform shaping circuit 9.
FIG. 9 is a plan view of a rotation detector 10 according to a third embodiment of the present invention, in which 0c is shared with an external terminal, as viewed from below, and the same or corresponding parts as in FIG. . FIG. 11 is a circuit diagram showing a specific configuration example of the waveform shaping circuit 9 in FIG. 10. The same or corresponding parts as those in FIG. 8 are denoted by the same reference numerals and description thereof is omitted.

Referring to FIG. 10 and FIG.
A terminal 81c serving as a positive terminal of the waveform shaping circuit 9
Is connected to a ribbon lead 91 (see FIG. 10) provided by the connector 70, for example, by welding or the like, and one end thereof is extended and exposed in the connector 21 (see the broken line), and the voltage signal Vd generated from the coil 70 is externally provided. Supply.

On the other hand, a terminal 81d serving as a negative electrode terminal
Is connected to the ribbon lead 91 of the waveform shaping circuit 9 by, for example, welding as in the case of the positive electrode terminal 81c.
It is connected to the ground (see FIG. 11) in the waveform shaping circuit 9 via the terminal 81b and is commonly grounded.

As described above, the terminal of the connector section 21 has a 4-pole configuration using the rotation detector 10 in which the waveform shaping circuit 9 is integrated, and the voltage signal V
By configuring the terminal for transmitting d with one terminal, it is possible to further reduce the size without impairing the above-described effect.

In addition, the rotation angle signal Rθ and the electric signal V
By supplying the two-system signal E to the outside via one connector section 21, the mounting work on the engine 1 can be simplified. Also, the negative electrode terminal 81d of the coil 70
Is grounded in common with the ground of the waveform shaping circuit 9 and the number of terminals to the outside is reduced, so that the rotation detector 10 integrated with the waveform shaping circuit 9 can be configured at low cost.

Embodiment 4 In each of the above-described embodiments, the abnormality of the signal detection plate 50 is regarded as an abnormality of the magnetic protrusion 5.
The case where the step Δh of 1 is used as the determination value γ has been described as an example, but the abnormality determination unit 42 can determine various types of abnormality. For example, the gap G (the signal detection plate 50)
It is needless to say that it is also possible to determine the angular position and number between the magnetic protrusions 51, the eccentricity abnormality, and the like.

Embodiment 5 FIG. Further, the signal detection plate 50 used in the engine 1 has been described as an example of the moving body, but the abnormality determination unit 42 can be applied to any moving body regardless of the rotating body, and the same effect can be obtained. Can play.

[0157]

As described above, according to the first aspect of the present invention, there is provided an apparatus for judging abnormalities of a plurality of magnetic projections provided on a moving body, wherein the magnetic projection is provided opposite to the magnetic projections. A magnetic transducer that detects an abnormality in the magnetic projection based on an electric signal from the magnetoelectric converter. The abnormality determination means includes a calculation means for calculating a determination value based on the peak value deviation of the electric signal, and a comparison determination means for comparing the determination value with an abnormality determination criterion. There is an effect that an abnormality judging device for a magnetic projection can be obtained which is reduced in size and reduced in size and cost.

According to a second aspect of the present invention, in the first aspect, the calculating means calculates the average value of the peak values of the electric signal, and calculates the correction coefficient based on the average value. And a correction coefficient calculating means for correcting the peak value deviation by using at least the correction coefficient to obtain a determination value. Thus, there is an effect that an abnormality determination apparatus for a magnetic protrusion having improved reliability can be obtained.

According to a third aspect of the present invention, in the second aspect, the average value calculating means uses the number m of samples of the electric signal to be latched, and uses the average value VAVG of the peak value V (i). the (i), is calculated by _{VAVG (i) = Σ n =} i-m + 1 i V (n) / m, the correction coefficient calculating means, the average value VAVG
Using the lower limit value VAVG (i) low of (i) and the constants a and b, the correction coefficient α (i) is calculated as the average value VA
When VG (i) is equal to or larger than the lower limit value VAVGlow, α (i) = a × {VAVG (i) −VAVGlow}
+ B, and the average value VAVG (i) is equal to the lower limit value VAVG.
When the peak value is smaller than low, α (i) = 1 is set, and the calculating means uses the peak value V (i) to calculate the peak value deviation ΔV.
(I) is calculated by ΔV (i) = V (i) −V (i + 1), and the determination value γ (i) corrected using the average value VAVG (i) and the correction coefficient α (i) is calculated as follows: γ (i) = α (i) × ΔV (i) / VAVG (i) × 1
00 [%], and the comparison / judgment means judges the abnormality of the magnetic projection when the judgment value γ (i) exceeds a predetermined threshold value, so that a reliable judgment can be made and the reliability is improved. This has the effect of obtaining an apparatus for determining abnormality of the magnetic projections.

According to a fourth aspect of the present invention, in the third aspect, the comparison / judgment means compares the judgment value γ (i) with a single threshold value, so that the configuration of the comparison / judgment means is simplified. There is an effect that an abnormality determination device for the magnetic protrusion can be obtained.

According to a fifth aspect of the present invention, in the first aspect, the movable body is a rotating plate, and the magnetoelectric converter is disposed on the coil wound on the core and on the axis of the core. It consists of an electromagnetic pickup including a magnet, and the electric signal consists of a voltage signal output from the electromagnetic pickup, so that a normal rotation detector can be used in common with a magnetoelectric converter, further reducing the work labor and miniaturizing. In addition, there is an effect that an abnormality judging device for a magnetic projection which can realize cost reduction can be obtained.

According to claim 6 of the present invention, in claim 5, the moving body is a signal detecting plate connected to the engine, and the magnetoelectric converter is formed on the signal detecting plate. A rotation detector disposed opposite to the magnetic protrusion, the rotation detector including a waveform shaping circuit that outputs a rotation angle signal corresponding to the rotation of the engine; and the electric signal is a voltage signal input to the waveform shaping circuit. Is obtained by branching the magnetic protrusions, so that there is an effect that a magnetic protrusion abnormality determination device that is further reduced in size and cost can be obtained.

According to the seventh aspect of the present invention, in the sixth aspect, the output terminal of the electric signal is integrated into the connector portion having the output terminal of the rotation angle signal, so that the size is further reduced. In addition, there is an effect that an abnormality judging device for a magnetic projection which can realize cost reduction can be obtained.

[Brief description of the drawings]

FIG. 1 is a block diagram schematically showing a first embodiment of the present invention.

FIG. 2 is an enlarged side view showing a main part of the first embodiment of the present invention.

FIG. 3 is a waveform chart showing an electric signal to an abnormal magnetic projection according to the first embodiment of the present invention.

FIG. 4 is a characteristic diagram showing a relationship between a determination value γ before correction calculation and an average value VppAVG according to the first embodiment of the present invention.

FIG. 5 is a characteristic diagram showing a relationship between a determination value γ and a gap G after the correction calculation according to the first embodiment of the present invention.

FIG. 6 is a block diagram schematically showing a second embodiment of the present invention.

FIG. 7 is a sectional view showing a magnetoelectric converter used in Embodiment 2 of the present invention and shared with a rotation detector.

FIG. 8 is a plan view of a magnetoelectric converter shared with a rotation detector used in Embodiment 2 of the present invention as viewed from below.

FIG. 9 is a circuit diagram showing a specific configuration example of a waveform shaping circuit in a rotation detector used in Embodiment 2 of the present invention.

FIG. 10 is a plan view of a magnetoelectric converter shared with a rotation detector used in Embodiment 3 of the present invention as viewed from below.

FIG. 11 is a circuit diagram showing a specific configuration example of a waveform shaping circuit in a rotation detector used in Embodiment 3 of the present invention.

FIG. 12 is a block diagram schematically showing a conventional magnetic judging unit abnormality judging device.

FIG. 13 is an enlarged side view showing an arrangement of a laser displacement meter used in a conventional magnetic protrusion abnormality determination device.

FIG. 14 is a cross-sectional view showing a rotation detector used in a conventional magnetic protrusion abnormality determination device.

FIG. 15 is a plan view of a connector portion of a rotation detector used in a conventional magnetic protrusion abnormality determination device as viewed from below.

FIG. 16 is a circuit diagram showing a specific configuration example of a waveform shaping circuit in a rotation detector used in a conventional magnetic protrusion abnormality determination device.

FIG. 17 is a waveform diagram showing a voltage detection signal and a rotation angle signal output in relation to a general signal detection plate.

FIG. 18 is a waveform diagram showing a variation of a general rotation angle signal due to a difference in rotation speed.

FIG. 19 is a waveform diagram showing a voltage signal and a rotation angle signal for an abnormally small magnetic projection in a general rotation detector.

FIG. 20 is a waveform diagram showing a voltage signal and a rotation angle signal for a slightly smaller magnetic protrusion in a general rotation detector.

FIG. 21 is an enlarged side view showing an arrangement of a dial gauge used in a conventional magnetic protrusion abnormality determination device.

[Explanation of symbols]

Reference Signs List 1 engine, 2 cores, 3 magnets, 9 waveform shaping circuit, 10 rotation detector, 15 magnetoelectric converter, 21 connector, 42 abnormality determination means, 43 arithmetic unit, 44
Comparison determination device, 50 signal detection plate, 51 magnetic protrusion, 51e abnormal magnetic protrusion, 52 recess, 70
Coil, G air gap, Rθ rotation angle signal, Vd voltage signal, VE electric signal, γ judgment value, Δh step.

Claims (7)

[Claims] 1. An apparatus for determining an abnormality of a plurality of magnetic projections provided on a moving body, comprising: a magnetoelectric converter arranged to face the magnetic projection; and an electric signal from the magnetoelectric converter. Abnormality judging means for judging abnormality of the magnetic projection portion based on the, the magnetoelectric converter converts the air gap change between the magnetic projection portion and the electric signal according to the magnetic flux change and outputs the electric signal, The abnormality judging means includes an arithmetic means for calculating a judging value based on a peak value deviation of the electric signal, and a comparing judging means for comparing the judging value with an abnormality judging standard. Judgment device. 2. The arithmetic unit includes: an average value arithmetic unit that calculates an average value of the peak values of the electric signal; and a correction coefficient arithmetic unit that calculates a correction coefficient based on the average value. The apparatus according to claim 1, wherein the peak value deviation is corrected using a coefficient to obtain the determination value. 3. The average value calculating means calculates an average value VAVG (i) of the peak values V (i) using the number m of samples of the electric signal to be latched, VAVG (i) = Σ _{n = i−m + 1} ⁱ V (n) / m, and the correction coefficient calculating means calculates a lower limit value VAVG (i) low of the average value VAVG (i),
And using the constants a and b, the correction coefficient α
(I) is calculated by changing the average value VAVG (i) to the lower limit value VAVGlo.
If w or more, α (i) = a × {VAVG (i) −VAVGlow}
+ B, and the average value VAVG (i) is equal to the lower limit value VAVG.
When it is smaller than low, α (i) = 1 is set, and the arithmetic means uses the peak value V (i) to calculate the peak value deviation ΔV (i), ΔV (i) = V (i) ) -V (i + 1), and a determination value γ (i) corrected using the average value VAVG (i) and the correction coefficient α (i).
Γ (i) = α (i) × ΔV (i) / VAVG (i) × 1
3. The calculation according to claim 2, wherein the comparison determination unit determines the abnormality of the magnetic projection when the determination value γ (i) exceeds a predetermined threshold. Abnormality judgment device for magnetic projections. 4. The comparison determination means according to claim 3, wherein said determination value γ
4. The apparatus according to claim 3, wherein (i) is compared with a single threshold value. 5. The moving body is a rotating plate, wherein the magnetoelectric converter comprises an electromagnetic pickup including a coil wound around a core and a magnet disposed on an axis of the core. The apparatus according to claim 1, wherein the signal is a voltage signal output from the electromagnetic pickup. 6. The moving body is a signal detecting plate connected to an engine, and the magnetoelectric converter is a rotation detector arranged to face a magnetic projection formed on the signal detecting plate. The rotation detector includes a waveform shaping circuit that outputs a rotation angle signal corresponding to the rotation of the engine, and the electric signal is obtained by branching a voltage signal input to the waveform shaping circuit. The apparatus for determining abnormality of a magnetic projection according to claim 5. 7. The abnormality judging device according to claim 6, wherein the output terminal of the electric signal is integrated into a connector having the output terminal of the rotation angle signal. .