JP2008111738A - Thickness measurement apparatus and program - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a thickness measurement apparatus and a thickness measurement program for inexpensively and simply measuring a thickness of an object to be measured. <P>SOLUTION: If an excitation current flows from a reference signal generating section 2 and an eddy current flows in the object to be measured, an eddy current detecting section 3 outputs an induction output corresponding to the eddy current to a phase detecting section 6. A phase shifting section 5 generates a shift signal as a shift signal generated by a shift signal generating section 4 and shifted by a predetermined detection phase (e.g. 90°). The phase detecting section 6 detects a phase of an eddy current signal outputted from an eddy current detecting section 3 based on the shift signal outputted from the phase shifting section 5. A phase delay detecting section 7a detects a phase delay of the eddy current signal when the eddy current signal is detected at the predetermined detection phase (e.g. 90°). A thickness measuring section 7f measures the thickness of the object to be measured based on the phase delay of the eddy current detected by the phase delay information detecting section and correlation relationship information stores in a correlation relationship information storing section 7e. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to a thickness measuring apparatus and a thickness measuring program for measuring the thickness of a measurement object.

  The conventional thickness measuring apparatus includes a first reflective laser displacement meter that irradiates a laser beam on the upper surface of the steel material, receives reflected light from the upper surface, and measures the distance to the upper surface of the steel material, and a lower surface of the steel material. A second reflection type laser displacement meter that irradiates laser light, receives reflected light from the lower surface, and measures the distance to the lower surface of the steel material; A C-shaped frame that supports the reflective laser displacement meter at the bottom, and an arithmetic processing unit that calculates the thickness of the steel material based on the measurement results of the first and second reflective laser displacement meters (for example, Patent Document 1). In such a conventional thickness measuring apparatus, the first and second reflective laser meters are moved by moving the C-shaped frame so that the steel material is positioned in the gap between the upper and lower portions of the C-shaped frame. Are irradiated on the upper surface and the lower surface of the steel material, respectively, and the arithmetic processing unit measures the thickness of the steel material based on the output signals of the first and second reflection type laser meters.

JP-A-8-233538

  In the conventional thickness measuring device, a driving device for driving the C-shaped frame is required to position the first and second reflective laser meters with respect to the steel material, and the device becomes large and complicated. There is a point. Further, in the conventional thickness measuring apparatus, it is difficult to accurately position the first and second reflective laser meters with respect to the steel material, and the thickness of the steel material cannot be measured with high accuracy. There is. Furthermore, in the conventional thickness measuring apparatus, it is necessary to measure the thickness of a steel material using a pair of reflection type laser meters, and there is a problem that the apparatus becomes expensive.

  An object of the present invention is to provide a thickness measuring apparatus and a thickness measuring program that can measure the thickness of an object to be measured easily and inexpensively.

The present invention solves the above-mentioned problems by the solving means described below.
In addition, although the code | symbol corresponding to embodiment of this invention is attached | subjected and demonstrated, it is not limited to this embodiment.
The invention according to claim 1, the measuring object _{(S 1, ..., S N} ) thickness _{(t 0, ..., t n} ) A thickness measuring apparatus for measuring, an eddy current in the object to be measured A phase lag detector (7a) for detecting the phase lag (φ ₀ ,..., Φ _n ) of the eddy current signal representing the time change of the eddy current when generated, and the detection result of the phase lag detector It is a thickness measuring device (1) provided with the thickness measurement part (7f) which measures the thickness of the said measurement object based on it.

  According to a second aspect of the present invention, in the thickness measuring apparatus according to the first aspect, the phase lag detecting unit detects a phase lag of the eddy current signal when the eddy current signal is detected at a predetermined detection phase. This is a thickness measuring device.

  According to a third aspect of the present invention, in the thickness measurement apparatus according to the second aspect, the phase lag detector detects a phase lag of the eddy current signal when the eddy current signal is detected at a detection phase near 90 °. It is a thickness measuring device characterized by detecting.

According to a fourth aspect of the present invention, there is provided the thickness measuring apparatus according to any one of the first to third aspects, wherein the phase lag detecting unit is provided for each measurement object (S ₁ ,..., S _N ). Is a thickness measuring device that detects a phase delay (φ ₀ ,..., Φ _n ) of the eddy current signal when the eddy current signal is detected at a detection phase corresponding to.

According to a fifth aspect of the present invention, in the thickness measurement apparatus according to any one of the first to fourth aspects, the thickness measurement unit includes a phase delay (φ ₀ ,..., Φ of the eddy current signal. _n ) and the thickness (t ₀ ,..., t _n ) of the measurement objects (S ₁ ,..., S _N ) and the phase lag of the eddy current signal detected by the phase lag detector ( phi _0, ..., based on the phi _n), the thickness (t ₀ of the measuring object, ..., the thickness measuring device and measuring the t _n).

The invention of claim 6 is a thickness measurement program for measuring the thickness (t ₀ ,..., T _n ) of the measurement object (S ₁ ,..., S _N ), A phase lag detection procedure (S500) for detecting a phase lag (φ ₀ ,..., Φ _n ) of an eddy current signal representing a time change of the eddy current when a current is generated, and detection in the phase lag detection procedure A thickness measurement program for causing a computer to execute a thickness measurement procedure (S600) for measuring the thickness of the measurement object based on a result.

  According to a seventh aspect of the present invention, in the thickness measurement program according to the sixth aspect, the phase lag detection procedure detects a phase lag of the eddy current signal when the eddy current signal is detected at a predetermined detection phase. A thickness measurement program including a procedure.

  According to an eighth aspect of the present invention, in the thickness measurement program according to the seventh aspect of the invention, the phase lag detection procedure is configured to detect a phase lag of the eddy current signal when the eddy current signal is detected at a detection phase near 90 °. It is a thickness measurement program characterized by including the procedure to detect.

The invention of claim 9 is the thickness measurement program according to any one of claims 6 to 8, wherein the phase delay detection procedure is performed for each of the measurement objects (S ₁ ,..., S _N ). Is a thickness measurement program including a procedure for detecting a phase delay (φ ₀ ,..., Φ _n ) of the eddy current signal when the eddy current signal is detected at a detection phase corresponding to.

The invention of claim 10 is the thickness measurement program according to any one of claims 6 to 9, wherein the thickness measurement procedure includes a phase delay (φ ₀ ,..., Φ of the eddy current signal. _n ) and the thickness (t ₀ ,..., t _n ) of the objects to be measured (S ₁ ,..., S _N ) and the phase lag of the eddy current signal detected in the phase lag detection procedure ( A thickness measurement program including a procedure of measuring the thickness (t ₀ ,..., t _n ) of the measurement object based on (φ ₀ ,..., φ _n ).

  According to the present invention, the thickness of the measurement object can be measured easily and inexpensively.

Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings.
FIG. 1 is a configuration diagram schematically showing a thickness measuring apparatus according to an embodiment of the present invention. FIG. 2 is a circuit diagram schematically showing an eddy current detector of the thickness measuring apparatus according to the embodiment of the present invention. FIG. 3 is a waveform diagram schematically showing signal processing of the phase detector of the thickness measuring apparatus according to the embodiment of the present invention. FIG. 3A shows the waveform of the reference signal output by the reference signal generator. 3B shows the waveform of the phase shift signal output from the phase shift signal generator, and FIG. 3C shows the waveform of the phase shift signal output from the phase shift unit. Here, the vertical axis shown in FIG. 3 is the output voltage (V), and the horizontal axis is the time (sec).

  A measuring object S shown in FIG. 1 is an object whose thickness is measured by the thickness measuring apparatus 1. The measuring object S is, for example, an iron pillar that constitutes a support for a train track by assembling a steel material that is a kind of section steel such as angle steel or H-section steel.

  The thickness measuring device 1 is a device that measures the thickness of the measuring object S. The thickness measuring device 1 generates an eddy current in the measuring object S to detect a phase delay of the eddy current signal, and measures the thickness of the measuring object S based on the phase delay of the eddy current signal. As shown in FIG. 1, the thickness measuring apparatus 1 includes a reference signal generation unit 2, an eddy current detection unit 3, a phase shift signal generation unit 4, a phase shift unit 5, and a phase detection unit 6. A processing unit 7 and the like are provided.

  The reference signal generator 2 is a means for generating a reference signal. For example, as shown in FIG. 3A, the reference signal generator 2 generates an AC signal (reference signal) having a predetermined frequency and inputs the AC signal as an input signal to the eddy current detector 3. And so on. The reference signal generator 2 outputs a continuous wave AC signal that does not vary as shown in FIG. 3A to the eddy current detector 3 so that the eddy current detector 3 can accurately detect the eddy current.

  The eddy current detection unit 3 shown in FIG. 1 is a means for detecting eddy currents generated in the measurement object S, such as a detection coil using a mutual induction type coil that detects eddy currents generated in the measurement object S. It is. As shown in FIG. 2, the eddy current detection unit 3 includes exciting coils 3a and 3b, induction coils 3c and 3d, variable resistors 3e and 3f, output terminals 3g and 3h, and the like. The excitation coils 3a and 3b are coils that generate a magnetic field so that an eddy current is generated in the measurement object S. The excitation coil 3a is disposed to face the measurement object S, and the excitation coil 3b is an excitation coil. It is connected in series with 3a and used in an air-core state. The induction coils 3c and 3d are coils that generate an electromotive force by electromagnetic induction when an eddy current is generated in the measurement object S, and are bridge-connected to the variable resistors 3e and 3f. The induction coil 3c is disposed to face the measuring object S, and the induction coil 3d is used in an air-core state. An alternating current (excitation current) output from the reference signal generator 2 flows through the induction coils 3c and 3d. The variable resistors 3e and 3f are resistors whose resistance values can be adjusted, and zero adjustment is performed so that the output of the bridge becomes zero when the exciting coil 3a and the induction coil 3c are not opposed to the measuring object S. Is done. The output terminals 3g and 3h are terminals for outputting an induced electromotive force corresponding to the eddy current generated in the measuring object S, and a difference between the induced outputs is output between the output terminals 3g and 3h. When the eddy current detection unit 3 causes an excitation current to flow from the reference signal generation unit 2 to the excitation coils 3a and 3b, the excitation coils 3a and 3b generate an induced magnetic field and an eddy current flows to the measurement object S. Are output from the output terminals 3g and 3h to the phase detector 6.

  The phase shift signal generator 4 shown in FIG. 1 is means for generating a phase shift signal. The phase shift signal generator 4 generates a pulse signal having a predetermined pulse width synchronized with the AC signal generated by the reference signal generator 2 as shown in FIG. As shown in FIG. The phase shift signal generator 4 generates a phase shift signal when the AC signal output from the reference signal generator 2 is positive, and outputs a phase shift signal when the AC signal output from the reference signal generator 2 is negative. Does not generate a signal.

  The phase shifter 5 shown in FIG. 1 is means for shifting the phase of the phase shift signal generated by the phase shift signal generator 4. For example, as shown in FIG. 3C, the phase shift unit 5 shifts the phase of the phase shift signal generated by the phase shift signal generation unit 4 by a predetermined detection phase (for example, 90 °). And a phase shifter for inputting the phase shift signal to the phase detector 6 as a reference signal. As shown in FIG. 3C, the phase shifter 5 opens and closes the gate in synchronization with the reference signal output from the reference signal generator 2.

  The phase detector 6 shown in FIG. 1 is means for phase-detecting the eddy current signal output from the eddy current detector 3. For example, the phase detector 6 is configured to phase the eddy current signal output from the eddy current detector 3 (difference between the induction outputs generated by the induction coils 3c and 3d) based on the phase shift signal output from the phase shift unit 5. It detects and converts into a phase detection signal (DC signal) and outputs it. As shown in FIG. 3C, the phase detection unit 6 outputs the eddy current signal output from the eddy current detection unit 3 for the time during which the phase shift unit 5 opens the gate (gate open time). To 7a. The phase detection unit 6 obtains a maximum output when the detection phase is 0 ° so that changes in the generation of eddy current signals can be easily detected, and outputs a signal proportional to the cosine wave to the phase lag detection unit 7a.

  The arithmetic processing unit 7 shown in FIG. 1 is means for performing predetermined arithmetic processing on the eddy current signal output from the phase detection unit 6. For example, the arithmetic processing unit 7 detects the phase lag of the eddy current signal output from the phase detection unit 6 and measures the thickness of the measuring object S based on the phase lag. The arithmetic processing unit 7 is a personal computer or the like that executes a predetermined process in accordance with a thickness measurement program for measuring the thickness of the measurement object S. The arithmetic processing unit 7 includes a phase lag detection unit 7a, a phase lag information storage unit 7b, a detection phase information storage unit 7c, a detection phase setting unit 7d, a correlation information storage unit 7e, and a thickness measurement unit 7f. , A measurement result storage unit 7g, a measurement result output unit 7h, a program storage unit 7i, a control unit 7j, and the like.

  The phase lag detector 7a is a means for detecting the phase lag of the eddy current signal representing the time change of the eddy current when an eddy current is generated in the measuring object S. The phase lag detector 7 a detects the phase lag of the phase detection signal (eddy current signal) output from the phase detector 6. The phase lag detection unit 7a detects a phase lag of the eddy current signal when the eddy current signal is detected at a predetermined detection phase (for example, a detection phase in the vicinity of 90 °), and the control unit uses the phase lag as phase lag information. Output to 7j. When measuring the thicknesses of a plurality of different types of measurement objects S such as steel materials, the phase lag detection unit 7a detects eddy current signals at a detection phase corresponding to each measurement object S. The phase lag of this eddy current signal is detected.

FIG. 4 is a waveform diagram schematically showing a phase detection signal output from the phase lag detector of the thickness measuring apparatus according to the embodiment of the present invention.
The vertical axis shown in FIG. 4 is the output voltage (V) of the eddy current signal, and the horizontal axis is the angle (°). The solid line waveforms W ₀ ,..., W ₃ shown in FIG. 4 are detected when the measurement object S has thicknesses t ₀ ,..., T ₃ (t ₀ <t ₁ <t ₂ <t ₃ ), respectively. shows the output voltage when at the time of detection by the phase 90 °, the waveform W ₁ of a two-dot chain line, ..., W ₃ is the measuring object S is the thickness t ₁ respectively, ..., in the case of t _3, the detection phase The output voltage when detecting at 0 ° is shown. _{φ 0, ..., φ 3 (} φ 0 <φ 1 <φ 2 <φ 3) are respectively the measuring object S is the thickness t _0, ..., in the case of t _3, when detected by the detection phase 90 ° Shows the phase lag of the output voltage. As shown in FIG. 4, when detecting the eddy current signal by the detection phase 0 °, the thickness t ₀ as shown by the two-dot chain line, ..., the signal level of the higher output voltage t ₃ is increased is lowered However, there is no phase lag in the output voltage. On the other hand, when an eddy current signal is detected at a detection phase of 90 °, as the thickness t ₀ ,..., T ₃ increases, the signal level of the output signal decreases and the phase delay φ ₀ ,. φ ₃ has become large, the thickness t _0, ..., phase delay φ ₀ in response to t _3, ..., _{φ 3} has occurred. For this reason, when detection is performed in the vicinity of the detection phase of 90 °, the signal level and phase of the output voltage change according to the thickness t ₀ ,..., T ₃ of the measurement object S, and in the vicinity of the detection phase of 90 °. phase delay phi ₀ of detection and eddy current signals, ..., by detecting phi _3, the thickness t ₀ of the measuring object S, ..., it is possible to measure the t _3.

  FIG. 5 is a graph showing the relationship between the steel material thickness and the output voltage when the detection phase is 0 ° and the detection phase is 70 ° in the thickness measuring apparatus according to the embodiment of the present invention. FIG. 6 is a graph showing the relationship between the steel material thickness and the output voltage when the detection phase is around 90 ° in the thickness measuring apparatus according to the embodiment of the present invention. FIG. 7 is a graph showing the measurement results of the magnetic flux density around the eddy current detection unit of the thickness measuring apparatus according to the embodiment of the present invention.

  The vertical axis shown in FIGS. 5 and 6 is the output voltage (V) of the eddy current signal, the horizontal axis is the steel thickness (mm) of the measuring object S, and the steel used as the measuring object S is generally used. It is an angle steel of structural rolled steel. The vertical axis shown in FIG. 7 is the magnetic flux density ratio, and the magnetic flux density around the induction coils 3c and 3d when the magnetic flux density closest to the induction coils (detection coils) 3c and 3d of the eddy current detector 3 is used as a reference. Is the ratio. The horizontal axis represents the distance (mm) from the induction coils 3c and 3d of the eddy current detector 3. The graph shown in FIG. 5 represents the relationship between the steel material thickness and the output voltage when the excitation frequency is 6 Hz, the phase detection is 0 °, and the phase detection is 70 °. As shown in FIG. 5, there is no correlation between the steel thickness and the output voltage when the phase detection is 0 °, but when the phase detection is 70 °, the steel thickness is up to 8 mm between the steel thickness and the output voltage. There is a slight correlation.

  The graph shown in FIG. 6 represents the result of detecting in the region where the output voltage is near zero near the detection phase of 90 ° and outputting only the phase delay corresponding to the steel thickness. As shown in FIG. 6, when the phase detection is 90 °, the output voltage decreases as the steel thickness increases, and a clear correlation is recognized between the steel thickness and the output voltage. For this reason, it is considered that the steel material thickness can be measured when the detection phase is 70 ° to 90 °, and in particular, the steel material thickness can be accurately measured when the detection phase is 90 °.

  The graph shown in FIG. 7 is a graph showing the result of measuring the magnetic flux density around the induction coils 3c and 3d of the eddy current detector 3 with a gauss meter. As shown in FIG. 7, the magnetic flux density due to the induction coils 3c and 3d is not affected by being away from the induction coils 3c and 3d by 15 mm. Therefore, the shape of the steel material does not affect the measurement at a position 15 mm away from the induction coils 3c and 3d. it is conceivable that.

The phase lag information storage unit 7b shown in FIG. 1 is means for storing the detection result of the phase lag detection unit 7a. The phase delay information storage unit 7b is, for example, a memory that stores the phase delays φ ₀ ,..., Φ ₃ for each measurement object S as phase delay information as shown in FIG.

  The detection phase information storage unit 7c is means for storing the detection phase corresponding to each measurement object S. The detection phase information storage unit 7c is, for example, a memory that stores, as detection phase information, an optimal detection phase corresponding to the type of each steel material when the measurement object S is a steel material.

  The detection phase setting unit 7d is a means for setting the detection phase when detecting the eddy current signal according to the measurement object S. For example, when the measurement object S is a steel material, the detection phase setting unit 7d sets a detection phase according to the type of the steel material, and outputs the detection phase for each steel material to the control unit 7j as detection phase information. The detection phase setting unit 7d searches the detection phase information storage unit 7c using the type of the measurement object S as a search key when the type of the measurement object S is input from an input unit (not shown). The detection phase corresponding to is selected.

FIG. 8 is a diagram schematically showing the data structure of the correlation information storage unit of the thickness measuring apparatus according to the embodiment of the present invention.
The correlation information storage portion 7e, a phase lag phi ₀ of eddy current signals, ..., φ _n and the measurement object S _1, ..., the thickness of the S _N t _0, ..., means for storing the correlation between the t _n It is. The correlation information storage portion 7e, for example, as shown in FIG. 8, the measuring object S _1, ..., a phase lag phi ₀ for each S _N, ..., φ _n and the thickness t _0, ..., and t _n The correlation is stored as correlation information.

1 is a means for measuring the thicknesses t ₀ ,..., T _n of the measuring objects S ₁ ,..., S _N based on the detection result of the phase lag detection unit 7a. The thickness measurement unit 7f measures the object based on the phase lags φ ₀ ,..., Φ _{n of} the eddy current signal detected by the phase lag information detection unit and the correlation information stored in the correlation information storage unit 7e. The thicknesses t ₀ ,..., T _n of S ₁ ,..., S _N are measured, and the measurement results are output to the control unit 7j as thickness measurement information.

The measurement result storage unit 7g is means for storing the measurement result of the thickness measurement unit 7f. Measurement result storage unit 7g is, for example, measuring the thickness measuring part 7f is the measuring object S _1, ..., the thickness t ₀ of each S _N, ..., and the like memory for storing t _n.

The measurement result output unit 7h is means for outputting the measurement result of the thickness measurement unit 7f. The measurement result output unit 7h is an interface (I / O) circuit or the like that connects the thickness measuring device 1 and an external device and inputs / outputs various information between them. The measurement result output unit 7h outputs the thicknesses t ₀ ,..., T _n for the measurement objects S ₁ ,..., S _N measured by the thickness measurement unit 7f to an external device such as a display device or a printing device.

The program storage unit 7i is the measuring object S _1, ..., the thickness t ₀ of the S _N, ..., a means for storing the thickness measurement program for measuring t _n. The program storage unit 7i is a memory that stores a thickness measurement program read from an information recording medium, a thickness measurement program taken in through a telecommunication line, and the like.

The control unit 7j is means (central processing unit (CPU)) for controlling various operations of the thickness measuring apparatus 1. The control unit 7j reads out the thickness measurement program from the program storage unit 7i and instructs the thickness measurement device 1 to execute a predetermined process. For example, the control unit 7j generates a reference signal in the reference signal generation unit 2, generates a phase shift signal in the phase shift signal generation unit 4, or shifts the phase shift unit 5 by a predetermined detection phase. Generating a signal for use, instructing the phase lag information storage unit 7b to store the phase lag information, reading out the detection phase information from the detection phase information storage unit 7c and outputting it to the detection phase setting unit 7d, or setting the detection phase The detection phase information output from the unit 7d is output to the phase shift unit 5, the correlation information is read from the correlation information storage unit 7e and output to the thickness measurement unit 7f, or the measurement object is input to the thickness measurement unit 7f. S _1, ..., S _n having a thickness of t _0, ..., or command the measurement of t _n, or stores the thickness measurement information in the measurement result storage unit 7 g, the thickness measurement information to the measurement result output section 7h Or output. As shown in FIG. 1, the control unit 7j includes a reference signal generation unit 2, a phase shift signal generation unit 4, a phase shift unit 5, a phase delay detection unit 7a, a phase delay information storage unit 7b, and a detection phase information storage unit. 7c, detection phase setting unit 7d, correlation information storage unit 7e, thickness measurement unit 7f, measurement result storage unit 7g, measurement result output unit 7h, program storage unit 7i, etc. Connected by means.

Next, the operation of the thickness measuring apparatus according to the embodiment of the present invention will be described.
FIG. 9 is a flowchart for explaining the operation of the thickness measuring apparatus according to the embodiment of the present invention. Below, it demonstrates centering around operation | movement of the control part 7j.
In step (hereinafter referred to as S) 100 shown in FIG. 9, the control unit 7j shown in FIG. 1 reads the thickness measurement program. When a power switch (not shown) is turned on, power is supplied to the thickness measuring device 1, and the control unit 7j reads the thickness measurement program from the program storage unit 7i and causes the arithmetic processing unit 7 to start a series of processes.

In S200, the control unit 7j determines whether or not the detection phase is set. The measuring object S ₁ shown in FIG. 8, ..., the kind of S _N is input to the control unit 7j from the input unit, not shown, the measuring object S _1, ..., detects the detection phase corresponding to S _N The detection phase setting unit 7d extracts from the phase information storage unit 7c, sets this detection phase as detection phase information, and outputs it to the control unit 7j. When the control unit 7j determines that the detection phase information is input from the detection phase setting unit 7d, the process proceeds to S300. On the other hand, when the control unit 7j determines that the detection phase information is not input from the detection phase setting unit 7d, for example, a display for calling attention to set the detection phase on a display device (not shown) is displayed on the measurement result output unit. The control unit 7j instructs through 7h, and the control unit 7j repeats the determination until detection phase information is input from the detection phase setting unit 7d.

  In S300, the control unit 7j instructs the reference signal generation unit 2 to generate the reference signal. As a result, the reference signal as shown in FIG. 3A is output from the reference signal generator 2 to the eddy current detector 3, and the reference signal flows through the exciting coils 3a and 3b shown in FIG. Eddy current is generated. When an eddy current is generated in the measuring object S, an electromotive force is generated in the induction coils 3 c and 3 d, and an eddy current signal is input from the eddy current detection unit 3 to the phase detection unit 6.

  In S400, the control unit 7j instructs the phase shift signal generation unit 4 to generate the phase shift signal. As a result, the phase shift signal as shown in FIG. 3 (B) is output to the phase shifter 5 by the phase shift signal generator 4 and set by the detection phase setting unit 7d as shown in FIG. 3 (C). The phase shift unit 5 outputs the phase shift signal shifted in the detection phase (for example, 90 °) to the phase detection unit 6. As a result, the phase detector 6 detects the phase of the eddy current signal output from the eddy current detector 3 based on the phase shift signal output from the phase shifter 5, and the phase shifter 5 opens the gate. The phase detector 6 causes the phase lag detector 7a to output the eddy current signal output from the eddy current detector 3 only during the open time.

In S500, the phase lag φ _0, ..., the control unit 7j to command the detection of phi _n to the phase lag detection unit 7a. For instance, as shown in FIG. 4, when detecting the eddy current signal by the detection phase 90 °, the waveform W ₀ shown by the solid line in the figure, ..., the thickness t ₀ as shown by W _3, ..., depending on t ₃ Phase delays φ ₀ ,..., Φ ₃ occur. As a result, the thickness t ₀ of the measuring object S, ..., in order to measure the t _3, the phase delay phi ₀ of eddy current signals phase detection unit 6 outputs, ..., a phi ₃ is a phase lag detection section 7a Then, the phase delays φ ₀ ,..., Φ ₃ are output to the control unit 7j as phase delay information, and the phase delay information is recorded in the phase delay information storage unit 7b.

In S600, the measuring object S _1, ..., S _N having a thickness of t _0, ..., the control unit 7j to command the thickness measurement unit 7f measurements t _n. The measuring object S ₁ shown in FIG. 2, ..., the kind of S _N is input to the control unit 7j from the input unit, not shown, the measuring object S _1, ..., a correlation information corresponding to S _N The control unit 7j reads out from the correlation information storage unit 7e and outputs it to the thickness measurement unit 7f. Further, the control unit 7j reads out the phase lag information from the phase lag information storage unit 7b and outputs it to the thickness measurement unit 7f. As a result, the measuring object S ₁ with reference to the correlation information as the phase lag information thickness measuring unit 7f, ..., S _N having a thickness of t _0, ..., measured t _n, the measurement result is thick The thickness measurement information is output to the control unit 7j, and the thickness measurement information is recorded in the measurement result storage unit 7g.

The thickness measuring apparatus and the thickness measuring program according to the embodiment of the present invention have the following effects.
(1) In this embodiment, the measuring object S _1, ..., when caused the eddy current to S _N, the phase delay phi ₀ of eddy current signals indicating the time change of the eddy current, ..., a phi _n The thickness measurement unit 7f detects the thicknesses t ₀ ,..., T _n of the measurement objects S ₁ ,..., S _N based on the detection result of the phase delay detection unit 7a. . Therefore, the thicknesses t ₀ ,..., T _n of the measuring objects S ₁ ,..., S _N can be easily measured by the thickness measuring device 1 having a simple configuration.

(2) In this embodiment, the phase delay detector 7a detects the phase delays φ ₀ ,..., Φ _n of the eddy current signal when the eddy current signal is detected at a predetermined detection phase. Therefore, by detecting the eddy current signal in the region where the signal level of the eddy current signal is close to zero, the measuring object S _1, ..., the thickness t ₀ of the S _N, ..., phase delay corresponding to t _n to output a divided body, the measuring object S _1, ..., S _n having a thickness of t _0, ..., a t _n can be accurately measured. In particular, when the detection of the eddy current signal by the detection phase 90 °, the phase delay phi ₀ of eddy current signals, as shown in FIG. 4, ..., phi ₃ and the thickness t ₀ of the measuring object S, ..., and t ₃ , And the thicknesses t ₀ ,..., T ₃ of the measuring object S can be measured with high accuracy.

(3) In this embodiment, the measuring object S _1, ..., S phase delay of the eddy current signal when detecting the eddy current signal by the detection _{phase N} corresponding to each phi _0, ..., phase delay to phi _n The detection part 7a detects. Thus, for example, the measuring object S _1, ..., by switching the detection phase according to S _N, the measuring object S _1, ..., an eddy current signal at the appropriate detection phase depending on the material of the S _N detection, and the measuring object S _1, ..., S _n thickness for each t _0, ..., a t _n can be accurately measured.

(4) In this embodiment, the phase delay phi ₀ of eddy current signals, ..., phi _n the measuring object S _1, ..., the thickness t ₀ of the S _N, ..., and the correlation between the t _n, phase delay phase delay phi ₀ of eddy current signals detector 7a detects, ..., based on the phi _n, the measuring object S _1, ..., S _n having a thickness of t _0, ..., a t _n thickness measuring unit 7f Measure. Accordingly, the measuring object S _1, ..., S _N having a thickness of t _0, ..., can be easily measured in a short time t _n.

The present invention is not limited to the embodiment described above, and various modifications or changes can be made as described below, and these are also within the scope of the present invention.
For example, in this embodiment, a steel material such as angle steel is described as an example of the measurement object S, but the present invention is also applied to a rail abdomen that connects a rail head portion and a rail bottom portion of a rail on which a railway vehicle travels. Can be applied. Further, in this embodiment, the thickness of the measurement objects S ₁ ,..., S _N based on the phase delays φ ₀ ,..., Φ _n of the eddy current signal when the eddy current signal is detected at a predetermined detection phase. t _0, ..., but measures the t _n, the signal level and the phase delay phi ₀ of the eddy current signal, ..., phi ₃ and the thickness t ₀ of the measuring object S on the basis of, ..., a t ₃ It can also be measured. In this case, the signal level or the phase delay phi ₀ of eddy current signals, ..., may be configured such that the thickness measuring device 1 a selection unit for arbitrarily selecting at least one of phi ₃ is provided. Further, in this embodiment, the thickness measuring device 1 includes the reference signal generator 2 and the phase shift signal generator 4 separately. However, the reference signal generated by the reference signal generator 2 is used for phase shift. It can also be configured such that the signal generation unit 4 inputs the signal and the phase shift signal generation unit 4 generates the phase shift signal based on the reference signal.

It is a lineblock diagram showing roughly the thickness measuring device concerning the embodiment of this invention. It is a circuit diagram which shows roughly the eddy current detection part of the thickness measuring apparatus which concerns on embodiment of this invention. It is a waveform diagram which shows typically the signal processing of the phase detection part of the thickness measuring apparatus which concerns on embodiment of this invention, (A) shows the waveform of the reference signal which a reference signal generation part outputs, (B) is The waveform of the phase shift signal output from the phase shift signal generator is shown, and (C) shows the waveform of the phase shift signal output from the phase shift unit. It is a wave form diagram showing typically the phase detection signal which the phase lag detection part of the thickness measuring device concerning this embodiment outputs. It is a graph which shows the relationship between the steel material thickness and output voltage in the case of a detection phase 0 degree and a detection phase 70 degree in the thickness measuring apparatus which concerns on embodiment of this invention. It is a graph which shows the relationship between the steel material thickness and output voltage when the detection phase is around 90 ° in the thickness measuring apparatus according to the embodiment of the present invention. It is a graph which shows the measurement result of the magnetic flux density in the eddy current detection part periphery of the thickness measuring apparatus which concerns on embodiment of this invention. It is a figure which shows typically the data structure of the correlation information storage part of the thickness measuring apparatus which concerns on embodiment of this invention. It is a flowchart for demonstrating operation | movement of the thickness measuring apparatus which concerns on embodiment of this invention.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Thickness measuring apparatus 2 Reference signal generation part 3 Eddy current detection part 3a, 3b Excitation coil 3c, 3d Induction coil 3g, 3h Output terminal 4 Phase shift signal generation part 5 Phase shift part 6 Phase detection part 7 Arithmetic processing part 7a Phase delay detection unit 7b Phase delay information storage unit 7c Detection phase information storage unit 7d Detection phase setting unit 7e Correlation information storage unit 7f Thickness measurement unit 7g Measurement result storage unit 7h Measurement result output unit 7i Program storage unit 7j Control unit S , S _1, ..., S _n measurement object t _0, ..., t _n thickness φ _0, ..., φ _n phase lag W _0, ..., W ₃ waveform

Claims (10)

A thickness measuring device for measuring the thickness of a measurement object,
A phase lag detection unit for detecting a phase lag of an eddy current signal representing a time change of the eddy current when an eddy current is generated in the measurement object;
A thickness measurement unit that measures the thickness of the measurement object based on the detection result of the phase lag detection unit;
A thickness measuring device comprising: In the thickness measuring device according to claim 1,
The phase lag detector detects a phase lag of the eddy current signal when the eddy current signal is detected at a predetermined detection phase;
Thickness measuring device characterized by. In the thickness measuring device according to claim 2,
The phase lag detector detects a phase lag of the eddy current signal when the eddy current signal is detected at a detection phase near 90 °;
Thickness measuring device characterized by. In the thickness measuring device according to any one of claims 1 to 3,
The phase lag detection unit detects a phase lag of the eddy current signal when the eddy current signal is detected at a detection phase corresponding to each measurement object;
Thickness measuring device characterized by. In the thickness measuring device according to any one of claims 1 to 4,
The thickness measuring unit is based on the correlation between the phase lag of the eddy current signal and the thickness of the measurement object, and the phase lag of the eddy current signal detected by the phase lag detection unit. Measuring the thickness of objects,
Thickness measuring device characterized by. A thickness measurement program for measuring the thickness of a measurement object,
A phase lag detection procedure for detecting a phase lag of an eddy current signal representing a time change of the eddy current when an eddy current is generated in the measurement object;
A thickness measurement procedure for measuring the thickness of the measurement object based on a detection result in the phase lag detection procedure;
A thickness measurement program that causes a computer to execute. In the thickness measurement program according to claim 6,
The phase lag detection procedure includes a procedure of detecting a phase lag of the eddy current signal when the eddy current signal is detected at a predetermined detection phase;
Thickness measurement program characterized by In the thickness measurement program according to claim 7,
The phase lag detection procedure includes a procedure of detecting a phase lag of the eddy current signal when the eddy current signal is detected at a detection phase near 90 °.
Thickness measurement program characterized by In the thickness measurement program according to any one of claims 6 to 8,
The phase lag detection procedure includes a procedure of detecting a phase lag of the eddy current signal when the eddy current signal is detected at a detection phase corresponding to each measurement object.
Thickness measurement program characterized by In the thickness measurement program according to any one of claims 6 to 9,
The thickness measurement procedure is based on the correlation between the phase lag of the eddy current signal and the thickness of the measurement object, and the phase lag of the eddy current signal detected in the phase lag detection procedure. Including a procedure for measuring the thickness of the object,
Thickness measurement program characterized by

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