JP2004170192A - Metal detecting machine - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To store and display wide-ranged information related to a detected metal piece and metal detection, and to enhance reliability and detection control performance. <P>SOLUTION: This machine is provided with a detecting means 1 for detecting magnetically the detected metal piece, and a determination means 14 for determining the presence of the metal piece based on a signal from the detecting means. The determination means has a storage means 27 for storing set information, detection information, and the related information related to the detected metal piece and the metal detection, and a display 28 for displaying the set information, the detection information and the related information stored in the the storage means. The set information is stored to be set before an detection operation, comparison with the set information is executed in the operation to determine the presence of the metal piece and a characteristic thereof, and the the detection information, the related information and the like are displayed and/or stored when the contamination of the metal piece is determined. <P>COPYRIGHT: (C)2004,JPO

Description

[0001]
TECHNICAL FIELD OF THE INVENTION
The present invention relates to a process for producing or processing various products in the fields of food, chemical, pharmaceutical, textile, sewing, mining, etc. The present invention relates to a metal detector capable of determining the presence or absence of a test metal piece, which is a metallic foreign substance such as a part or a piece.
[0002]
[Prior art]
[Patent Document 1] JP-A-9-72885 [Patent Document 2] JP-A-9-72886 [Patent Document 3] JP-A-11-118766 [0003]
2. Description of the Related Art Conventionally, as a metal detector for detecting a metallic foreign substance mixed in a raw material such as food or a product, there is, for example, a metal detector 10 configured as shown in FIG.
[0004]
In FIG. 1, a metal detector 10 includes a detection head 1 that detects a metallic foreign substance, a discriminating device 4 that performs an amplification operation on a signal received from the detection head 1 to determine the presence or absence of metal contamination, It is constituted by a belt conveyor 5 and the like for transporting a subject so as to pass through a tunnel-like passage.
[0005]
The detection head 1 has an excitation coil 3 for generating a magnetic field and two reception coils 2a and 2b differentially connected to reduce the influence of disturbance while receiving a magnetic field generated from the excitation coil 3 inside the frame. And
[0006]
The receiving coils 2a and 2b are arranged side by side in a frame above the tunnel-shaped passage of the detection head 1, and the excitation coil 3 is arranged in a frame below the tunnel-shaped passage. The exciting coil 3 is arranged such that the central portion of the size thereof faces the middle point of the adjacent interval between the receiving coils 2a and 2b.
[0007]
By arranging the receiving coils 2a and 2b and the exciting coil 3 in this manner, the exciting coil is used when the subject placed on the conveyor 5 is passed through the tunnel-like passage of the detection head 1 using the principle of electromagnetic induction. The differentially connected receiving coils 2a and 2b capture the change in the interlinkage magnetic flux due to the metal piece as an induced electromotive force, and the discriminating device 4 performs amplification arithmetic processing on the change in the alternating magnetic flux due to the mixed metal flux. Metal pieces can be detected.
[0008]
[Problems to be solved by the invention]
However, in the conventional metal detector 10, when the received signal voltage input from the detection head 1 to the discriminating device 4 exceeds the voltage level for comparison set in the metal detector 10 in advance, the discriminating device is used. The received signal voltage is displayed as a numerical value or a bar graph on an LCD (Liquid Crystal Display) or the like provided in the LCD 4, a character indicating that the metal piece to be detected has been detected is displayed to alert the operator, Only a metal contamination signal (detection signal) is output to an apparatus for removing a specimen mixed with a test metal piece.
[0009]
For this reason, information such as the type and size of the detected test piece is unknown, and it is difficult to specify when and from which equipment or device the test piece was dropped and mixed. Since other wide-ranging related information cannot be stored or displayed, it is not possible to retroactively examine a matter to be known, so that there has been a problem that the reliability of the measured value and the detection management performance cannot be improved.
[0010]
Also, before starting the metal detector 10 at the start of work or the like, various test pieces 6 in which a standard metal ball 7 (for example, φ1.0 mm in diameter, made of Fe (iron) or the like) is embedded as shown in FIG. It is necessary to pass through the tunnel-like passage of the detection head 1 to test in advance whether the detection capability of the metal piece to be detected by the metal detector 10 maintains a predetermined management performance. There is a management problem that information such as the type and size of the various test pieces 6 and the history of the test cannot be stored or displayed.
[0011]
In view of the above problems, the present invention can store and display a wide range of relevant information related to a metal piece to be detected and metal detection, and can improve its reliability and detection management performance. It is an object of the present invention to provide a metal detector that can be used.
[0012]
[Means for Solving the Problems]
In order to solve the above problems, the present invention
A detection unit for magnetically detecting various types of metal pieces to be detected mixed with the subject, and a determination unit for determining the presence or absence of the metal pieces based on a signal received from the detection unit; Metal detector
The determining means is:
Setting information set for the test metal piece, detection information indicating that the test metal piece has been detected, and storage means capable of storing relevant information related to the test metal piece and metal detection,
Display means for displaying the setting information, detection information and related information stored in the storage means,
It can be stored to set the setting information before the detection operation,
Along with the setting information during the detection operation, it is possible to determine the presence or absence and characteristics of the test metal piece in the test object,
When it is determined that the test piece is mixed, both or both the detection information and the related information or only the detection information can be displayed and / or stored.
[0013]
According to the metal detector having such a configuration, in addition to the setting information set for the various test metal pieces to be detected and the detection information indicating that the test metal piece has been detected, the test piece And related information related to metal detection can also be stored and displayed, so that in addition to information such as the type and size of the detected metal piece and phase characteristics, for example, turning on the power and starting the conveyor, In addition, it is easy to confirm all wide-ranging items related to metal detectors, such as metal detection, changes in various set values, occurrence items, occurrence date and time, and easy identification of when and from which equipment or equipment was dropped and mixed. Therefore, the reliability and detection management performance of the metal detector can be improved.
[0014]
Also, when a test piece with a standard metal ball embedded at the start of business is passed through the tunnel-like passage of the detection head, and the test capability of the metal detector satisfies the management performance is also tested in advance, similarly, Relevant information such as the type, size, and phase characteristics of the metal piece as the management target, or various occurrence items and the date and time of occurrence can be stored and displayed. Quality assurance and safety management can be ensured.
[0015]
BEST MODE FOR CARRYING OUT THE INVENTION
Hereinafter, embodiments of a metal detector according to the present invention will be specifically described with reference to the drawings.
[0016]
FIGS. 1 to 5 are diagrams referred to for describing a metal detector 20 according to an embodiment of the present invention. In the metal detector 20, the same parts as those of the conventional metal detector 10 are denoted by the same reference numerals, and the same description as the conventional one will be omitted.
[0017]
As shown in FIG. 1, an excitation current is supplied to the excitation coil 3 of the detection head 1 to the metal detector 20, and a signal received from the reception coils 2a and 2b is amplified and subjected to arithmetic processing to be mixed into the subject. A discriminating device 14 for discriminating the presence or absence of a metallic foreign matter (a metal piece to be tested) and calculating information on the metallic foreign matter is provided.
[0018]
As shown in the block diagram of FIG. 2, the determination device 14 includes a high-frequency amplifier 21, a detector 22, a low-frequency amplifier 23, a filter 24, an A / D converter 25, an arithmetic processing unit 26, and a storage unit 27 ( A storage unit), an operation display unit 28 (display unit), a detection output unit 29 (output unit), a data output unit 30 (output unit), a printing unit 31 (printing unit), and an excitation output unit 32.
[0019]
The excitation output unit 32 of the discrimination device 14 is connected to the excitation coil 3 of the detection head 1, and supplies an excitation current to the excitation coil 3 in response to a command from the arithmetic processing unit 26. The high-frequency amplifier 21 is connected to the receiving coils 2a and 2b of the detection head 1, and receives output signals from the receiving coils 2a and 2b.
[0020]
The signals output from the receiving coils 2a and 2b are amplified at the high frequency amplifying unit 21 of the discriminating device 14 with the excitation frequency unchanged, and are converted into low frequency signals by the detector 22. The low-frequency signal is amplified by the low-frequency amplifier 23, and after the noise component contained in the low-frequency signal is reduced by the filter 24, the analog signal is converted from an analog signal to a digital signal by the A / D converter 25. Are input to the arithmetic processing unit 26.
[0021]
The arithmetic processing unit 26 compares the digital signal input from the A / D conversion unit 25 with the comparison voltage level set (stored) in the storage unit 27 for the type of the test piece to be detected. Accordingly, it is determined whether or not a metal piece is mixed in the subject, and the characteristics of the mixed metal piece and other extensive information are calculated.
[0022]
The storage unit 27 stores setting information set for various types of test metal pieces to be detected and detection information indicating that the test metal pieces have been detected from the subject, and is calculated by the arithmetic processing unit 26. Extensive information such as the characteristics of the test piece, the result of the comparison operation with the setting information, and the date and time when the test piece was detected and the operating status at that time are related to the test piece and metal detection. Related information.
[0023]
The operation display unit 28 includes an LCD (liquid crystal display) for displaying setting information, detection information, related information, and the like, and various switches for operation. In addition, the LCD may be in a touch panel format so as to display a wide range of information related to the metal piece to be detected and the metal detection, and also to be able to operate.
[0024]
When the arithmetic processing unit 26 determines that the test piece is mixed with the test object, the detection output unit 29 outputs a metal mixing signal (detection information) to the test object mixed with the test piece. Is output to an apparatus for removing the test piece, and the data output unit 30 includes, in addition to detection information indicating that the test piece has been detected from the subject, extensive data relating to the test piece and the metal detection. The related information is output to an external device such as a personal computer.
[0025]
The printing unit 31 includes setting information set for various types of test metal pieces to be detected, detection information indicating that the test metal piece has been detected from the subject, and extensive information related to the test metal pieces and metal detection. The related information is printed out (printed) by a printer.
[0026]
Next, a method for extracting characteristics of the test piece will be described.
The vector diagram shown in FIG. 3 is based on the signal of the differential connection output voltage of the receiving coils 2a and 2b output through the high frequency amplifier 21 to the A / D converter 25 of the discriminator 14, and the arithmetic processing unit 26 This is for describing the processing operation when calculating the characteristics of the test piece.
[0027]
Since various kinds of actual metals have their own specific electrical conductivity and magnetic permeability, the signal of the differential connection output voltage of the receiving coils 2a and 2b is based on the magnetic and conductive properties of the metal pieces mixed into the subject. Is affected by the change of the linkage magnetic flux.
[0028]
Therefore, the arithmetic processing unit 26 calculates the differential connection output voltage (signal) of the receiving coils 2a and 2b, so that the characteristics of the test piece can be represented as a vector as shown in FIG. That is, the argument of the vector is determined by the conductivity and magnetic permeability specific to the type of metal, and the magnitude of the vector is determined in proportion to the size of the metal piece.
[0029]
For example, for iron (Fe), its characteristics can be represented as vectors A and A ′. The deflection angle theta ₅ vector A, are those determined as a unique argument iron by conductivity and magnetic permeability of the iron. The magnitudes of the vectors A and A 'are determined in proportion to the size of the iron piece. Here, it is assumed that the magnitudes of the vectors A and A ′ in FIG. 3 are determined by a φ1 mm iron ball.
[0030]
Here, the magnitude of the vector A is based on the maximum value of the differential connection output voltage of the receiving coils 2a and 2b when the subject is located on the receiving coil 2a side in the tunnel-like passage of the detection head 1. In addition, the magnitude of the vector A ′ is based on the maximum value of the differential connection output voltages of the receiving coils 2a and 2b when the subject is transported and comes to the position on the receiving coil 2b side.
[0031]
The differential connection output voltages of the receiving coils 2a and 2b indicate that the vector A and the vector A 'are opposite to each other when the subject is on the receiving coil 2a side and when the subject is on the receiving coil 2b side. , Their sizes are equal.
[0032]
Similarly, the characteristics of aluminum, lead, and stainless steel spheres each having a size of φ1 mm can be represented as a vector. In other words, the vectors representing the characteristics of the φ1 mm aluminum sphere are vectors B and B ′ whose declination is θ ₆ .
[0033]
Furthermore, the vector representing the characteristic of the lead sphere φ1mm is the vector C and C 'declination is theta _7. The vector representing the characteristics of the stainless steel ball having a φ1mm is the vector D and D 'declination is theta _8.
[0034]
As described above, since the conductivity and the magnetic permeability differ depending on the type of the metal, the deflection angles of the vectors representing the characteristics of the metal differ.
[0035]
Next, in FIG. 3, the virtual projection axis X _θn rotating about the origin is considered, and the angle of the fixed coordinate axis with the X axis is θ _n . If the magnitude of the vector A representing the φ1 mm iron ball is represented as | A |, the projection length of the vector A onto the virtual projection axis X _θn is | A | cos (θ ₅ −θ _n ). Thus, it is possible to the projection length of the virtual projection axis X _.theta.n of vector A as a function of theta _n.
[0036]
Then, the projection length of the virtual projection axis X _.theta.n of vectors A, theta _n is the maximum value when it matches with the polarization angle theta ₅ vector A, whose magnitude is | A | become. Further, when theta _n is from deflection angle theta ₅ of vector A of 90 ° minus the angle theta _1, its value will be the minimum 0.
[0037]
Similarly, even if the test piece of metal aluminum, each sphere of lead or stainless steel, the virtual projection axis projection length in the X _.theta.n of each vector can be expressed as a function of theta _n. The maximum value of the projection length of each vector and θ _{n at} that time, and the minimum value and θ _{n at} that time are also calculated.
[0038]
As described above, the projection length of each vector on the virtual projection axis X _θn for the test metal pieces of various materials is expressed as a function of the phase angle θ _n to obtain a phase characteristic curve as shown in FIG. Can also be expressed.
[0039]
For example, | A | phase characteristic curve of cos (θ ₅ -θ _n) represents the phase characteristic curve of the iron pieces having a size of Ø1 mm. Then, the maximum value when the detection signal indicating by a point P ₅ is maximum | A | and declination theta ₅ at that _time, and, and its minimum value of 0 when the detection signal indicating by a point P ₁ is the smallest deflection angle theta ₁ at that time can be a representative value that indicates the characteristics of the iron ball having a size of Ø1 mm.
[0040]
Similarly, for aluminum ball φ1mm, | B | cos its maximum value when the detection signal shown by P ₆ terms of the phase characteristic curve becomes the maximum _{(θ 6 -θ n) | B} | and at that time The declination θ ₆ , the minimum value 0 when the detection signal indicated by the point P ₂ is the minimum, and the declination θ _{2 at} that time can be representative values indicating the characteristics, and a lead ball of φ1 mm Also, the characteristics of stainless steel balls can be indicated by their phase characteristic curves and representative values.
[0041]
The storage unit 27 stores a representative value indicating such a characteristic of the metal piece as a digital value for each type and size of the metal, and the operation display unit 28 stores a phase based on these representative values. Characteristic curves and the like can be displayed.
[0042]
Therefore, by detecting a standard test piece whose metal type and size are known in advance by the detection head 1, these representative values can be set in the storage unit 27 (setting information is stored). That is, these representative values are set using a test piece for each type and size of metal to be detected. For example, when it is desired to detect an iron piece of φ1 mm or more, these representative values are set using test pieces of iron balls φ1 mm, φ1.2 mm, and φ1.5 mm.
[0043]
As described above, by detecting the various test pieces with the detection head 1, a representative value indicating the characteristic of the metal piece to be detected can be set. If is known, a representative value indicating the characteristic may be manually set in the storage unit 27 by operating the operation display unit 28.
[0044]
Vs shown in FIG. 4 is a comparison voltage level set for determining whether or not a mixed metal is mixed in the detection signal, and a common level can be used for various metals. . When the maximum value of the detection signal of the phase characteristic curve exceeds the comparison voltage level Vs as a result of the calculation by the calculation processing unit 26 based on the detection signals from the receiving coils 2a and 2b, the following operation is performed. Is
[0045]
That is, for the metal piece mixed into the subject, the declination when the voltage in the detection signal is the maximum value and the declination when the voltage is the minimum value are compared with the data of various metals set in the storage unit 27. Then, the type of the metal piece is determined. Then, the size of the metal piece is determined by comparing the maximum value of the voltage in the detection signal with the set data of various sizes of the metal piece of that type.
[0046]
The detection information indicating that a metal piece has been detected from the subject, the type, size, date and time of occurrence of the metal piece, and other extensive information are stored in the storage unit 27 as relevant information related to the metal piece to be detected and the metal detection. And the information can be displayed on the LCD of the operation display unit 28.
[0047]
For example, when the phase characteristic of an unknown metal piece mixed into the subject is equivalent to that of an iron ball test piece and the magnitude of the maximum value of the detection signal is between φ1.0 mm and φ1.2 mm. As shown in FIG. 5, in the LCD of the operation display unit 28, in the case of iron, an item indicating that a metal piece having a size of not less than φ1.0 mm and not more than φ1.2 mm is detected is a phase characteristic. The maximum and minimum values of the voltage in the curve detection signal, the voltage level for comparison Vs, the date and time of occurrence, and the like are displayed.
[0048]
Further, in the storage unit 27, the content itself displayed on the LCD of the operation display unit 28 is stored as one of related information relating to the metal piece to be detected and the metal detection, and the related information or a part thereof is stored in the data output unit. The data can be output to an external device such as a personal computer via the printer 30 or printed out from the printing unit 31. Further, the detection information may be output to an external device such as a personal computer via the data output unit 30 or may be printed out from the printing unit 31 together with the related information or a part thereof.
[0049]
Then, in the device for removing the test object mixed with the test piece, the relevant information or a part thereof may be output together with the detection information via the detection output unit 29, and only the detection information may be output. You may make it output.
[0050]
If the maximum value of the phase characteristic curve of the test piece mixed in the test object exceeds the maximum value of the phase characteristic curve of the set test piece, the test piece is May be displayed to indicate that the size is larger than the metal sphere in the test piece set.
[0051]
According to the metal detector 20 having such a configuration, in addition to the setting information set for the various test metal pieces to be detected and the detection information indicating that the metal piece has been detected from the subject, Since the related information relating to the metal test piece and the metal detection can be stored and displayed, in addition to the information such as the type, size, and phase characteristics of the detected metal piece, for example, power-on or conveyor It is easy to confirm all wide-ranging matters related to metal detectors, such as start-up, metal detection, change of various set values, various occurrence items, date and time of occurrence, etc. Since the identification becomes easy, the reliability and the detection management performance of the metal detector 20 can be improved.
[0052]
In addition, when the test piece 6 in which the standard metal ball 7 is embedded at the start of operation is passed through the tunnel-like passage of the detection head 1 to test in advance whether the detection capability of the metal detector 20 satisfies the management performance. Similarly, related information such as the type, size, and phase characteristics of a metal piece, which is a management target, or various occurrence items and the occurrence date and time can be stored and displayed, so that the detection management performance of the metal detector 20 can be improved. Therefore, quality assurance and safety management of the subject can be reliably performed.
[0053]
In the present embodiment, the receiving coils 2a and 2b are arranged in a frame above the tunnel-shaped passage of the detection head 1, and the exciting coil 3 is arranged in a frame below the tunnel-shaped passage of the detection head 1. However, if the receiving coils 2a and 2b can appropriately detect the change of the interlinkage magnetic flux due to the mixed metal piece of the AC exciting magnetic field by the exciting coil 3 as the induced electromotive force, these are used as the induced electromotive force. An arrangement method different from the embodiment may be adopted.
[0054]
Further, in the present embodiment, a method of using a common voltage level for various metals as a set comparison voltage level has been described. However, different comparison voltage levels that are appropriately determined for each metal. May be used.
[0055]
Further, in the present embodiment, the discriminating device 14 is provided with the detection output unit 29 and the data output unit 30 separately. However, by providing only the data output unit 30, a detection signal indicating that a metal piece has been detected is provided. Alternatively, both the test piece and the related information related to the metal detection may be output to another device. Instead of providing the printing unit 31, an external recording device (printer) may be provided and connected to the data output unit 30.
[0056]
In addition, for the storage, display, output, and printing, the test piece and the related information related to the metal detection, the type of the metal piece, the size, the phase characteristic, and the test piece such as the occurrence date and time as described above. Not only information on the pieces but also all occurrences related to the metal detector 20, such as power on / off, conveyor start / stop, operation / test mode, change of brand of the subject, error occurrence / elimination, in addition to the metal detection operation Extensive information such as manual setting, automatic setting, memory clear, all reset, change of voltage level for comparison, change of various set values, date and time of abnormality occurrence, etc. is stored as related information related to the test piece and metal detection. , Display, output, and printing.
[0057]
Further, the test piece of the metal piece stores the characteristics of the test results using the three types of φ1.0 mm, φ1.2 mm, and φ1.5 mm for the iron ball, the aluminum ball, the lead ball, and the stainless ball in the storage unit 27. Although the memory is stored, it is needless to say that the test may be performed on another metal, or the test may be performed using a test piece having a size different from that described above.
[0058]
【The invention's effect】
As described above, according to the metal detector according to the present invention, in addition to the setting information set for the various test metal pieces to be detected and the detection information indicating that the test metal piece has been detected, The related information relating to the detected metal piece and the metal detection can also be stored and displayed. In addition to the information such as the type and size of the detected metal piece and the phase characteristics, for example, power-on And wide range of matters related to metal detectors such as start-up of conveyors and conveyors, or detection of metals and changes of various set values, occurrences, date and time of occurrence, etc. And the like can be easily specified, so that the reliability and detection management performance of the metal detector can be improved.
[0059]
Also, at the start of operation, a test piece in which a standard metal ball is embedded is passed through the tunnel-like passage of the detection head, and similarly, when the detection capability of the metal detector satisfies the management performance in advance, similarly, Relevant information such as the type, size, and phase characteristics of the metal piece as the management target, or various occurrence items and the date and time of occurrence can be stored and displayed. Quality assurance and safety management can be ensured.
[Brief description of the drawings]
FIG. 1 is a front view showing a configuration of a metal detector 20 according to an embodiment of the present invention.
FIG. 2 is a block diagram showing a circuit configuration of a discrimination device 14 in FIG.
FIG. 3 is a vector diagram for explaining the operation contents of an operation processing unit 26 in FIG. 2;
FIG. 4 is a phase characteristic diagram of various metal pieces.
FIG. 5 is a diagram showing a display example of the LCD of the operation display unit 28.
FIG. 6 is a front view showing a configuration of a conventional metal detector 10.
FIG. 7 is a perspective view showing a test piece 6 in which a metal ball 7 is embedded.
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 1 Detection head 2a, 2b Receiving coil 3 Exciting coil 4 Discriminating device 5 Belt conveyor 6 Test piece 7 Metal ball 10 Metal detector 14 Discriminating device 20 Metal detector 21 High frequency amplifier 22 Detector 23 Low frequency amplifier 24 Filter unit 25 A / D conversion unit 26 Operation processing unit 27 Storage unit 28 Operation display unit 29 Detection output unit 30 Data output unit 31 Printing unit 32 Excitation output unit

Claims (5)

A detection unit for magnetically detecting various types of metal pieces to be detected mixed with the subject, and a determination unit for determining the presence or absence of the metal pieces based on a signal received from the detection unit; Metal detector
The determining means is:
Setting information set for the test metal piece, detection information indicating that the test metal piece has been detected, and storage means capable of storing relevant information related to the test metal piece and metal detection,
Display means for displaying the setting information, detection information and related information stored in the storage means,
It can be stored to set the setting information before the detection operation,
Along with the setting information during the detection operation, it is possible to determine the presence or absence and characteristics of the test metal piece in the test object,
A metal detector characterized by being able to display and / or store both the detection information and related information or only the detection information when it is determined that the test piece is mixed. The metal detector according to claim 1, wherein the determination unit includes a printing unit that can print all or a part of the setting information, the detection information, and the related information stored in the storage unit. The discriminating unit may determine all or a part of the setting information, the detection information, and the related information stored in the storage unit by using an external device such as a device for removing a test object mixed with a test piece and / or a personal computer. The metal detector according to claim 1 or 2, further comprising an output unit capable of outputting the output to an apparatus. The metal detector according to any one of claims 1 to 3, wherein the setting information and the related information stored in the storage unit are at least a type, a size, and a phase characteristic of the test metal piece. The metal detector according to any one of claims 1 to 4, wherein the related information stored in the storage unit includes various occurrence items, occurrence date and time, and various other various related items.

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