JP3380617B2 - Change amount detection device - Google Patents

Description

Description: BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for detecting various variations from the peak value of a pulse voltage generated between both ends of a linear body made of a soft magnetic material. And a change amount detection device. [0002] Generally, a phenomenon in which a potential difference occurs between both ends of a ferromagnetic material twisted in a magnetic field, that is, a so-called Matteuci effect is known. Traditionally,
Various devices utilizing the effect of this stake cow have been proposed. For example, Japanese Patent Application Laid-Open No. 62-200280 discloses
`` A stiletto effect element formed by winding an AC excitation coil around an amorphous alloy wire having high magnetostriction, a magnet that constantly applies a DC magnetic field to the trajectory of the stiletto effect element and the orbit of the magnetic substance to be detected, and A non-magnetic base for fixing a gap between the stubble effect element and a detection circuit which is conductively connected to both ends of the amorphous alloy wire and detects an output pulse voltage of the stiffness element to generate a signal; "A magnetic substance detection device is disclosed (hereinafter, referred to as prior art 1). In the prior art 1, when the magnetic body to be detected approaches the magnet, the DC magnetic field is attracted by the magnetic body to be detected having a large relative magnetic permeability, the DC magnetic flux passing through the amorphous alloy wire decreases, and the peak value of the output pulse is reduced. It is stated that the detection of the magnetic body to be detected can be performed reliably and stably by converting a change in the magnetic field into an electric signal. However, in the above-mentioned prior art 1, only the detection of the magnetic substance to be detected is performed, and other variations such as the speed of the magnetic substance to be detected cannot be detected. For this reason, it has been pointed out that it is not suitable for practical use. Accordingly, as disclosed in Japanese Patent Publication No. 63-54247, "Amorphous magnetic thin plate to which tension is applied on the front and back surfaces in directions opposite to each other and along the surface; end of the amorphous magnetic thin plate An electric signal output circuit connected to a portion; supporting means for supporting the amorphous magnetic thin plate in a state where tension is applied to the front and rear surfaces in directions opposite to each other along the surface; A magnetic field exciting means for changing the magnetic field applied to the amorphous magnetic thin plate by the exciting means, "the electric pulse generator has been proposed (hereinafter referred to as prior art 2). In the prior art 2, a sharp voltage pulse having a peak value which can be processed by a practical electric circuit without using a pickup coil can be obtained by applying a torsional force to the amorphous magnetic thin plate and applying an alternating magnetic field thereto. It can be used for a vehicle speed sensor, a distance meter, a position meter, and the like. [0005] In this case, according to the above-mentioned prior art 2, when used as a speed sensor for detecting the speed, for example, among the variations of the speed, the distance, and the position,
The moving speed of the permanent magnet (excitation means) is detected based on the frequency of the pulse generated by the thin amorphous magnetic plate. Therefore, especially when the moving speed of the permanent magnet is low, the number of generated pulses is reduced, and the resolution tends to be problematic,
As a result, there is a problem that the speed detection accuracy is inferior. An object of the present invention is to solve such a problem, and an object of the present invention is to provide a change amount detecting device capable of detecting various change amounts with high accuracy and reliability with a simple configuration. And [0007] In order to achieve the above object, the present invention provides a linear body formed of an amorphous alloy wire ,
An AC excitation coil wound around the linear body;
An alternating magnetic field applying means for applying an alternating magnetic field to the body, and a peak value of a pulse voltage generated between both ends of the linear body when the linear body is twisted , generated from the AC exciting coil.
Voltage detector that detects in synchronization with the exciting AC voltage
Detection means for a storage unit in which both ends of the linear body is pre-stored data about <br/> to form torsion angles the change amount corresponding to the peak value of the pulse voltage, said detection means The torsional angle corresponding to the peak value of the pulse voltage detected at
Control means for outputting the degree based on the data stored in the storage means. In the variation detecting apparatus according to the present invention, when a pulse voltage is generated between both ends of the linear body in the alternating magnetic field, the peak value of the pulse voltage is detected by the detecting means. Then, based on the data stored in the storage means, the amount of change corresponds to the detected peak value of the pulse voltage.
A torsion angle between both ends of the linear body is obtained. For this reason, variously changing angles can be easily and accurately detected from changes in the peak value of the output pulse voltage. An embodiment of a change amount detecting apparatus according to the present invention will be described below in detail with reference to the accompanying drawings. In FIG. 1, reference numeral 10 denotes an angle detecting device which is a variation detecting device according to a first embodiment of the present invention. The angle detecting device 10 includes an amorphous wire (amorphous alloy wire) 12 which is a linear body made of a soft magnetic material,
An alternating magnetic field applying means 14 for applying an alternating magnetic field to the amorphous wire 12; a voltage detector (detecting means) 16 for detecting a peak value of a pulse voltage generated between both ends of the amorphous wire 12; A memory (storage means) 18 for storing data relating to an angle (amount of change) corresponding to the high value in advance, and an angle corresponding to the peak value of the pulse voltage detected by the voltage detector 16 are stored in the memory 1.
A control unit (control means) 20 for outputting to the angle output unit 19 based on the data stored in the control unit 8. The alternating magnetic field applying means 14 includes an AC exciting coil 22 wound around the amorphous wire 12 which is pulled in the axial direction with a predetermined tension (described later), and an oscillator 24 connected to the AC exciting coil 22. And The voltage detector 16 detects a peak value of a pulse voltage generated between both ends of the amorphous wire 12 when the amorphous wire 12 is twisted, in synchronization with an exciting AC voltage generated from the AC exciting coil 22. In order to perform this operation, it is connected to a phase detection unit 28 via a gate setting unit 26. The input terminal of the phase detection unit 28 is connected to the AC exciting coil 22, and the gate setting unit 26 connected to the output terminal of the phase detection unit 28 is connected to the peak position of the oscillator 24 to avoid noise. It is set so that the output voltage is taken in only several tens μsec before and after. The output terminal of the voltage detector 16 is connected to a peak hold unit 30. The peak hold unit 30
The peak value of the output pulse voltage is stored. The half width of the peak (the time from when the pulse voltage rises to 1/2 of the peak value to when it falls to 1/2 of the peak value) is 10 to 20 μsec. Next, a description will be given of an operation of creating data relating to the angle corresponding to the peak value of each pulse voltage output from both ends of the amorphous wire 12 in the angle detecting device 10 configured as described above. First, the diameter is 125 μm and the length is 28 cm.
Is formed.
As a method for preparing the alloy, a high-purity metal having a purity of 99% or more is weighed with a target composition, a button alloy is prepared by arc melting, and the button alloy is pulverized to an appropriate size and supplied to a submerged spinning apparatus. went. The conditions for spinning in liquid are as follows:
cm, the rotation speed is 300 rpm, the nozzle diameter is 120 μm,
The injection pressure was 0.5 kgf using Ar as the injection gas.
/ Cm ² . As a result, the wire diameter was 125 μm (long side) and 115 μm (short side), and the composition was Fe _77.5 Si
An amorphous wire 12 of _7.5 B ₁₅ (wt%) was formed. [0015] As shown in FIG.
2 has a fixed upper end and is suspended.
A weight 40 of 00 g is attached, and a tension (16 kgf / mm ² ) is applied to the amorphous wire 12. An AC exciting coil 42 is wound around the amorphous wire 12,
An oscillator 44 is connected to the AC excitation coil 42. The AC excitation coil 42 has an inner diameter of 3 mm and a length of 12 c.
m, and the excitation conditions are a frequency of 1 kHz (sine wave) and a current of 100 mA. One ends of conductive wires (enamel wires) 46a and 46b are connected to upper and lower ends of the amorphous wire 12 by soldering, and the other ends of the conductive wires 46a and 46b are connected to an oscilloscope 48. This amorphous wire 12
A protractor 50 for detecting a twist angle between both ends of the amorphous wire 12 is disposed at a lower end side of the protruding portion. In FIG. 2, when the weight 40 is rotated in the direction of arrow A in a state where an AC magnetic field is applied to the amorphous wire 12 under the above-described excitation conditions, the amorphous wire 12 is twisted in the direction of arrow A. The oscilloscope 48 generates a potential difference between its two ends.
A waveform S _A pulse voltage generated across the sinusoidal S ₀ and the amorphous wire 12 due is displayed simultaneously (see Figure 3A). Next, when the weight 40 is rotated in the direction of arrow B, the weight 40 is moved to an intermediate position (the amorphous wire 1).
2B, the output becomes zero as shown in FIG. 3B. Weight 40 is further rotated in the direction B when the amorphous wire 12 is twisted in the direction of arrow B, the pulse voltage is generated between both ends of the amorphous wire 12, the waveform S _B sinusoidal S ₀ at the same time oscilloscopes 48 (see FIG. 3C). In this case, when the twist direction of the amorphous wire 12 is different, paying attention to a specific phase (FIGS. 3A to 3A).
3C, the polarity of the output is reversed. That is, when the amorphous wire 12 is twisted in the direction of arrow A, the waveform S _A pulse voltage peak value V _A becomes peak is outputted when the sine wave S ₀ transitions from positive to negative. On the other hand, when the amorphous wire 12 is twisted in the direction of arrow B, the peak value V is a peak on the negative side waveform S _B of the pulse voltage when the sine wave S ₀ transitions from positive to negative
_B is output. That is, when the amorphous wire 12 is twisted clockwise with respect to the axial direction, a tensile stress acts on the clockwise magnetization component and a compressive stress acts on the counterclockwise magnetization component. In this state, when exciting at a certain frequency, the output pulse voltage (Machiushi voltage) is obtained as a positive (or negative) value in a specific phase. Next, when the amorphous wire 12 is twisted counterclockwise, the magnetization component receives the opposite stress, and the polarity of the output pulse voltage is reversed. Thereby, the direction in which the amorphous wire 12 is twisted can be specified. The amorphous wire 12 is twisted through a protractor 50 in the directions of arrows A and B at predetermined angles, and
The relationship between the pulse voltage output from and the peak value was detected. This result is shown in FIG. Then, data relating to the twist angle of the amorphous wire 12 corresponding to the peak value of the pulse voltage output from the amorphous wire 12 is obtained as a map or an arithmetic expression (relational expression).
Is stored in the memory 18. The tension is applied to the amorphous wire 12 in order to adjust the variation in the pulse voltage generated between both ends of the amorphous wire 12 and to correct the bending generated when the amorphous wire 12 is formed. . This tension is 0.01 to 50 kgf /
It is preferably set within the range of mm ² . 0.01
If it is less than kgf / mm ² , the desired tensile state cannot be maintained, and if it exceeds 50 kgf / mm ² , the output pulse voltage becomes unstable as shown in FIG. The relationship shown in FIG. 5 shows the result when a 1 kHz, 15 V sine wave was excited using the FeSiB-based amorphous wire 12 to which a twist of 180 ° / 12 cm was applied. Further, the frequency of the excitation AC is 10H
It is preferable to set within the range of z to 10 kHz (see FIGS. 6A to 6E and FIG. 7). That is, 10H
If it is less than z, the pulse voltage output from the amorphous wire 12 is small and the stability is poor (see FIG. 6A). On the other hand, if the frequency exceeds 10 kHz, the waveform is broken and it becomes difficult to read the peak value (peak) (see FIG. 6E). FIGS. 8A to 8F show the hysteresis characteristics of the torsion angle of the amorphous wire 12. FIG. As a result, the coercive force H could be stably maintained until the twist angle exceeded 720 ° / 10 cm, and the result that the measurable angle range was considerably wide was obtained. After the various conditions are set as described above, an angle detection operation is performed using the angle detection device 10 shown in FIG. This will be described in brief. In a state where an AC magnetic field is applied to the amorphous wire 12 via the oscillator 24, when a to-be-tested object (not shown) to which the amorphous wire 12 is attached is twisted, the amorphous wire 12 A pulse voltage is output between both ends. This pulse voltage is taken in by the voltage detector 16, and the phase detector 28 detects the phase of the excitation waveform (sine wave). Next, a signal is output from the phase detector 28 to the voltage detector 16 via the gate setting unit 26. Therefore, the pulse voltage can be detected in synchronization with the excitation waveform. The peak value of the pulse voltage is temporarily stored in the peak hold unit 30, and the peak value is input to the control unit 20.
In the control unit 20, the torsion angle corresponding to the peak value is read from the memory 18, or
The torsion angle is displayed on the angle output unit 19 (output). At this time, when the peak value input to the control unit 20 is unstable, it is preferable to integrate several times to obtain an average value. In this case, in the first embodiment, only by detecting the peak value of the pulse voltage generated when the amorphous wire 12 is twisted, the twist angle of the amorphous wire 12 is determined from the magnitude of the peak value. It can be easily detected. Furthermore, by synchronizing the pulse voltage and the excitation waveform, the reversal of the polarity can be detected, and the twist direction of the amorphous wire 12 can be detected.
Therefore, the torsion direction and the size of the test object on which the amorphous wire 12 is mounted can be simultaneously detected with a simple configuration, and the amorphous wire 12 having a small volume and the AC exciting coil 22 having a small outer diameter are used. This can be effectively applied to the detection of the angle of a minute drive unit, the measurement of the shaft torque of a robot, and the like. In the first embodiment, a sine wave is used as the excitation waveform. However, the present invention is not limited to this.
It is possible to use a triangular wave S ₁ shown in FIG. 9A and a square wave S ₂ shown in FIG. 9B. Next, a description will be given of a speed detector which is a change amount detector according to a second embodiment of the present invention. FIG.
In the figure, reference numeral 60 indicates a speed detecting device. The speed detecting device 60 includes an amorphous wire (amorphous alloy wire) 62 which is a linear body made of a soft magnetic material, and a magnetic field alternating with the amorphous wire 62. , A voltage detector (detection means) 66 for detecting a peak value of a pulse voltage generated between both ends of the amorphous wire 62, and a speed (amount of change) corresponding to the peak value of each pulse voltage. And a speed output unit based on the data stored in the memory 68. The memory (storage means) 68 stores data relating to the peak value of the pulse voltage detected by the voltage detector 66 in advance. And a control unit (control means) 70 for outputting the result to the control unit 69. A peak hold unit 71 is interposed between the voltage detector 66 and the control unit 70. The alternating magnetic field applying means 64 moves Nd relatively to the amorphous wire 62 in the direction of the arrow Y perpendicular to the axial direction of the amorphous wire 62 (the direction of the arrow X).
The multipole magnet 72 includes N-S poles arranged alternately so that magnetic pole boundaries are parallel. Next, a description will be given of an operation of creating data relating to the speed corresponding to the peak value of each pulse voltage output from both ends of the amorphous wire 62 in the speed detecting device 60 thus configured. First, as shown in FIG.
Fe _77.5 Si _7.5 B ₁₅ μm and 30 mm length (wt
%) Of the amorphous wires 62a and 62b are arranged on the base 80 in parallel with each other at a distance W. Crimping terminals 82a, 82b are connected to both ends of the amorphous wires 62a, 62b, respectively.
a and 82b are fixed to the base 80 via screws 84a and 84b. The base 80 includes an amorphous wire 62a,
A groove 86 is formed in a direction orthogonal to the extending direction of the groove 62b, and tension adjusting projections 88a and 88b are formed on both sides of the groove 86 in parallel with each other. One ends of copper wires 90a, 90b are connected to the crimp terminals 82a, 82b, and the other ends of the copper wires 90a, 90b are connected to an oscilloscope 92. The amorphous wires 62a and 62b are given a predetermined torsion by setting the mounting angle of the crimp terminals 82a and 82b, and further prepare a calibration table of the tension and the output voltage by weight in advance. The tightening state of the screws 84a and 84b is adjusted so that the output voltage is obtained. The multi-pole magnet 72 as a moving body has a length of 15
mm, the height is 5 mm and the width of the magnetic pole is 1 mm each.
An epoxy-based insulating film of 0 μm is formed. Then, the multipolar magnet 72 moves at a speed v in the direction of the arrow and passes under the amorphous wires 62a and 62b. At this time, each of the amorphous wires 62a, 62a
When b moves relative to the boundary of the magnetic field of the multipolar magnet 72 (the boundary where the magnetic poles are reversed), the pulse voltage has a time difference Δt between both ends of the amorphous wires 62a and 62b due to rapid reversal of magnetization. (Machiushi voltage) is output (see FIG. 12). Therefore, the speed v is calculated from the distance W and the time difference Δt (v = W / Δt). If the peak value of the pulse voltage at this time is detected, the relationship between the peak value and the speed can be obtained. The peak values corresponding to various speeds are detected (see FIG. 13), and the relationship is calculated, for example. It is stored in the memory 68 as an expression or a map. Further, in the speed detecting device 60, predetermined twist and tension are applied to the amorphous wire 62. The magnetic domains of the amorphous wire 62 are uniformly distributed in a non-magnetized state, and the amorphous wires 62 are biased by applying a twist to the magnetic domains. This is because, when the magnetic domain is biased, the amount of magnetization change at the time of magnetization reversal increases, and the output pulse voltage increases. Therefore, there is a state in which no pulse voltage is generated even when the magnetic field is changed, and this state is set such that the twist is 0 °. Therefore, the twist of the amorphous wire 62 is set within a range of 5 ° / 10 cm to 720 ° / 10 cm. When the torsion is less than 5 ° / 10 cm, the bias is not sufficient and the output pulse voltage decreases. On the other hand, when the torsion is increased, the saturation magnetization, coercive force and squareness ratio increase, and the pulse voltage increases. Unstable magnetization is not achieved, and the output becomes unstable and decreases (see FIGS. 8F and 14). For this reason, a twist exceeding 720 ° / 10 cm is not suitable for practical use. The tension of the amorphous wire 62 is
Set within the range of 0.01 to 50 kgf / mm ² .
If it is less than 0.01 kgf / mm ² , the desired tensile state cannot be maintained, and if it exceeds 50 kgf / mm ² , the output pulse voltage becomes unstable and decreases (see FIG. 5 and FIG. 5). See FIG. 15). Furthermore, the magnetic field distribution formed by the magnet is determined by the distance from the magnet surface. For this reason, in the measurement configuration shown in FIG. 11, the distance between the amorphous wires 62a and 62b and the multipolar magnet 72 is managed, and the strength of the magnetic field is measured with a DC Gauss meter to detect the relationship between the distance and the output pulse voltage. did. The result is shown in FIG.
It is shown in FIG. Thus, the strength of the magnetic field is 5G
(Gauss) or more is preferably maintained. After the various conditions are set as described above, speed detection is performed using the speed detection device 60 shown in FIG. At this time, the amorphous wire 62 is, for example, 9
While being twisted by 0 ° (300 ° / 10cm),
The tension is adjusted so that the output pulse voltage becomes 20 mV in an AC magnetic field of 10 Oe (Oersted) and 500 Hz. Therefore, a moving body (not shown) on which the multi-pole magnet 72 or the amorphous wire 62 is mounted is shown in FIG.
When the medium moves in the direction of arrow Y, the multipolar magnet 72 and the amorphous wire 62 pass relatively, and a pulse voltage is output from between both ends of the amorphous wire 62. After the pulse voltage is captured by the voltage detector 66, the peak value is temporarily stored in the peak hold unit 71, and the peak value is input to the control unit 70. In the control unit 70, a speed corresponding to the peak value is read from the memory 68 or calculated based on an arithmetic expression stored in the memory 68, and the speed is output to the speed output unit 69.
Display (output). In this case, in the second embodiment, the relative speed between the amorphous wire 62 and the multi-pole magnet 72 can be detected from the magnitude of the peak value of the pulse voltage output from the amorphous wire 62. . Therefore, there is no problem such as a decrease in resolution at a low speed, such as when detecting the speed from the frequency of the output pulse voltage, and the speed detection operation can be performed with high accuracy and efficiency. Can be In addition, many amorphous wires 6
By arranging the two in parallel, it is possible to continuously detect the speed of the moving body on which the multipolar magnet 72 is mounted.
Further, the speed detecting device 60 includes an amorphous wire 62
And the multi-pole magnet 72 as main components, and there is an advantage that the configuration is simplified and reduced in size at once. According to the variation detecting apparatus according to the present invention,
The following effects can be obtained. When a pulse voltage is generated between both ends of the linear body in the alternating magnetic field, the peak value of the pulse voltage is detected by the detecting means. Then, based on the data stored in the storage means, a twist formed by both ends of the linear body, which is an amount of change corresponding to the peak value of the detected pulse voltage , is formed.
Angle is obtained. For this reason, various changing angles can be easily and accurately detected from the change in the peak value of the output pulse voltage.
The angle can be detected with high accuracy.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a schematic configuration diagram of an angle detection device according to a first embodiment of the present invention. FIG. 2 is a configuration diagram for detecting a relationship between a peak value of an output pulse voltage stored in the angle detection device and a torsion angle. FIG. 3 is a relationship diagram between an excitation waveform and an output pulse voltage;
3A is a relationship diagram when the polarity is positive, FIG. 3B is a relationship diagram when the output is 0, and FIG. 3C is a relationship diagram when the polarity is negative. FIG. 4 is a relationship diagram between a peak value of an output pulse voltage and a torsion angle. FIG. 5 is a relationship diagram between tension and output pulse voltage. 6A and 6B are diagrams showing a relationship between an excitation frequency and an output pulse voltage. FIG. 6A shows a case where the excitation frequency is 5 Hz, and FIG.
6C is a relationship diagram when the excitation frequency is 10 Hz, FIG. 6D is a relationship diagram when the excitation frequency is 10 kHz, and FIG. 6E is a relationship diagram when the excitation frequency is 30 kHz. FIG. 7 is a diagram showing a relationship between the excitation frequency and an output pulse voltage. 8A and 8B are diagrams showing hysteresis characteristics of a torsion angle. FIG. 8A shows a case where the torsion angle is 0 °, FIG. 8B shows a case where the torsion angle is 90 °, and FIG.
For 0 °, FIG. 8D shows that for a twist angle of 360 °,
FIG. 8E is a diagram illustrating a case where the twist angle is 540 °, and FIG. 8F is a diagram illustrating a case where the twist angle is 720 °. 9A and 9B are waveform diagrams when an excitation waveform other than a sine wave is used. FIG. 9A is a waveform diagram for a triangular wave, and FIG. 9B is a waveform diagram for a square wave. FIG. 10 is a schematic configuration diagram of a speed detection device according to a second embodiment of the present invention. FIG. 11 is a configuration diagram for detecting a relationship between a peak value of an output pulse voltage stored in the speed detection device and a speed. FIG. 12 is a waveform diagram of a pulse voltage output by the speed detection device. FIG. 13 is a relationship diagram between a peak value of an output pulse voltage and a speed. FIG. 14 is a relationship diagram between a twist angle and an output pulse voltage. FIG. 15 is a relationship diagram between tension and output pulse voltage. FIG. 16 is a diagram illustrating a relationship between a magnetic field (distance from a magnet surface) and an output pulse voltage. [Description of Signs] 10 ... Angle detecting device 12 ... Amorphous wire 14 ... Alternating magnetic field adding means 16 ... Voltage detector 18 ... Memory 20 ... Control unit 22 ... AC exciting coil 24 ... Oscillator 26 ... Gate setting unit 28 ... Phase detecting unit Reference Signs List 30 peak holding unit 40 weight 42 AC exciting coil 44 oscillator 60 speed detecting devices 62, 62a, 62b amorphous wire 64 alternating magnetic field adding means 66 voltage detector 68 memory 70 control unit 71 peak Hold part 72: Multi-pole magnet

──────────────────────────────────────────────────続 き Continuation of the front page (56) References JP-A-4-263307 (JP, A) JP-A-58-117718 (JP, A) JP-A-62-9488 (JP, A) (58) Field (Int.Cl. ⁷ , DB name) G01B 7/30 G01D 5/20

Claims (1)

(57) Claims: 1. A linear body formed of an amorphous alloy wire , and an AC exciting coil wound around the linear body .
An alternating magnetic field applying means for applying an alternating magnetic field to the body; and a crest value of a pulse voltage generated between both ends of the linear body when the linear body is twisted .
Voltage detection that detects in synchronization with the excitation AC voltage generated from
Detecting means having a detector, and the linear amount being a change amount corresponding to the peak value of each pulse voltage.
Storage means for storing in advance data relating to the torsion angle between the two ends of the body, and the torsion angle corresponding to the peak value of the pulse voltage detected by the detection means is stored in the storage means. A change amount detection device comprising: control means for outputting based on data.