JP2015111075A - Diagnosis device of metal detector, and metal detector - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a diagnosis device of a metal detector and a metal detector that accurately diagnose a state of decline in metal detection capability, and enable occurrence of problems such as a wrong detection and the like to be prevented beforehand.SOLUTION: A diagnosis device of a metal detector diagnosing a metal detector main body 10 including a detection unit 12 detecting a change in magnetic field in a detection range R and a detection control unit 14 controlling an operation of the detection unit comprises: an operation condition switch unit 51 that allows the detection unit 12 to operate under a plurality of categories of operation conditions; an individual determination unit 52 that individually determines an allowable degree for an operation result under the operation condition for each category; a coupling determination unit 53 that combines the operation results for each category of two categories or more based on the operation result for each category to prepare a coupling operation result related to a metal detection performance, and executes at least one coupling determination of determining the allowable degree for the result; and an overall determination unit 55 that executes an overall determination of determining whether or not the metal detection performance is accepted in response to the individual determination result and the overall determination result.

Description

  The present invention relates to a diagnostic device and a metal detector for a metal detector, and more particularly to a diagnostic device for a metal detector that performs metal detection using a magnetic field and a metal detector having a diagnostic function including the same.

  2. Description of the Related Art Conventionally, a metal detector that detects the presence of a metal foreign object or a metal component in an object to be inspected or a missing component including a metal using a magnetic field has been known.

  In such metal detectors, depending on the type of object to be inspected and the required foreign substance detection capability, defective products can be detected by using defective products or using foreign material samples embedded with foreign metal equivalents. In general, it is possible to ensure detection accuracy of a foreign object or a missing part by setting detection conditions that enable the detection and confirming in advance that a defective product or the like can be detected by the setting.

  As such a conventional metal detector, for example, an operation confirmation processing unit that determines whether or not the detection unit operates correctly using a foreign material sample, and a display that displays the result of foreign object determination and the result of the operation confirmation processing In the operation confirmation processing unit, it is known that the detection unit determines whether or not the detection unit operates correctly for the foreign material sample specified for each product type (for example, see Patent Document 1).

  Considering the influence of external electromagnetic noise on the metal detector, prepare multiple detection operation frequencies of the magnetic field detection means for the set frequency of the magnetic field generation means, and set the detection operation frequency that can suppress the noise level below a predetermined value. What is selected and set is also known (see, for example, Patent Document 2).

JP 2009-31149 A Japanese Patent No. 4633830

  However, in the conventional metal detector as described above, when the magnetic field is disturbed depending on the installation environment or use state, the metal detection capability changes, but the function of accurately diagnosing the metal detection capability is provided. It was missing. Therefore, when a problem such as a false detection occurs, the cause cannot be easily identified, and it is necessary for a skilled service person to isolate the problem and deal with it, reducing the operating rate of the production line using a metal detector There was a case where I was allowed to.

  Also, extraneous electromagnetic noise from the electric equipment around the inspection area becomes large, or objects with a large magnetic field effect on the back and joints of the conveyor belt, which are difficult to see, or the conveyor belt is charged, Even when the detection sensitivity required for foreign object detection has run out, the reduced detection capability is used until a specific inspection object requiring detection of minute foreign objects is detected or a false detection occurs. Could not grasp. For this reason, it has been difficult to prevent problems such as erroneous detection.

  Therefore, the present invention provides a metal detector diagnostic device and a metal detector capable of accurately diagnosing a lowered state of metal detection capability and preventing the occurrence of problems such as false detection. It is an object of the present invention to provide a metal detector diagnostic device and a metal detector that can easily identify the cause of the deterioration of the metal detector.

  In order to solve the above-mentioned problems, a diagnostic apparatus for a metal detector according to the present invention includes (1) a detection for detecting a change in a magnetic field in an inspection region through which an inspection object passes to detect a metal in the inspection object. And a detection device for diagnosing a metal detector comprising a detection control means for controlling the operation of the detection means, wherein the detection means is preset in cooperation with the detection control means. Operating condition switching means for operating under a plurality of types of operating conditions, individual determination means for individually determining the allowable degree of the operating result for each type of operating condition among the plurality of types, and the plurality of types of operating conditions Based on the operation result under the operation condition for each type of the above, the operation result under the operation condition for each of the two or more types is combined to create at least one combined operation result related to the detection performance of the metal, The combined operation A combination determination means for performing at least one combination determination for determining an acceptable degree of the image, and determining whether the metal detection performance is good or not according to the result of the individual determination and the result of the at least one combination determination. And comprehensive determination means for executing comprehensive determination.

  In the present invention, when the metal detection capability changes due to one or more specific factors, the individual determination result and the combination determination result obtained by the operation under a plurality of types of operation conditions in which those factors change, Accordingly, the result of comprehensive determination for determining the quality of the metal detection performance changes. Therefore, it is possible to easily grasp the reduced state of the metal detection capability from the result of the comprehensive determination, and it is possible to prevent problems such as erroneous detection from occurring. In addition, if the individual determination result or the combination determination result is used, it is possible to easily identify the factor that decreases the metal detection capability.

  The metal detector diagnostic device of the present invention is (2) the metal detector includes moving means for moving the object to be inspected with respect to the inspection area, and the operating condition switching means includes the plurality of types. As the operating condition, a first operating condition for detecting a change in the magnetic field in the inspection area by the detecting means while moving the test piece for the detection sensitivity test of the detecting means to the inspection area by the moving means; A second operating condition for detecting a change in the magnetic field in the inspection area by the detecting means while operating the moving means without using the test piece, and the coupling determining means includes the one coupling determination As described above, when the detection means operates under the first operating condition, the detection signal level corresponding to the test piece detection sensitivity, and when the detection means operates under the second operating condition. It may be configured to determine whether preset a margin between the peak level of the detection signal of the change in the magnetic field.

  With this configuration, the environmental impact and the like in the usage state of the metal detector increase, the detection signal level corresponding to the test piece detection sensitivity when the detection means is operated under the first operating condition, and the detection means in the second operation. If there is no margin between the peak level of the detection signal of the change in the magnetic field in the inspection region when operating under conditions, the overall determination result is a failure determination. Therefore, before the deterioration of the metal detection capability progresses to a level that can cause a problem such as false detection, the comprehensive determination result becomes a failure determination, so that the user can be notified of the decrease in metal detection capability, and the problem of false detection or the like Can be surely prevented from occurring.

  The metal detector diagnostic device of the present invention outputs (3) first diagnostic information corresponding to the result of the comprehensive determination and second diagnostic information corresponding to the result of the individual determination or the combination determination. Diagnostic information output means may be provided.

  With this configuration, when the permissible degree as the individual determination result or the combination determination result changes according to the change in the metal detection capability, and the quality determination result of the metal detection performance changes, the first corresponding to the result of the comprehensive determination From the output of the diagnostic information, it is possible to easily grasp the lowered state of the metal detection capability. Therefore, it is possible to prevent problems such as erroneous detection from occurring. In addition, the factor that decreases the metal detection capability can be easily identified by the output of the second diagnosis information corresponding to the individual determination result or the combination determination result.

  In the diagnostic apparatus for a metal detector according to the present invention, (4) the diagnostic information output means, when the first diagnostic information is information indicating that the metal detection performance is not good, the individual determination or Second diagnosis information corresponding to the result of the combination determination may be displayed.

  This configuration makes it easy to identify the factors that reduce the metal detection capability when there is no room in sensitivity to detect minute metal objects against external electromagnetic noise and other environmental effects. By displaying possible second diagnostic information, necessary maintenance can be performed accurately in a timely manner.

  The metal detector diagnostic apparatus according to the present invention includes: (5) a magnetic field generator that causes the detection means to generate an alternating magnetic field having a set frequency included in a predetermined frequency range in the inspection region; and the inspection object. Including a magnetic field detector that detects a change in the alternating magnetic field caused by passing through the alternating magnetic field at a detection operating frequency corresponding to the set frequency, and the plurality of types of operating conditions include: The magnetic field generation unit is different from each other in at least one of the strength of the generated magnetic field, the detection operation frequency of the detection unit in the magnetic field detection unit, and the presence / absence of the operation of the moving unit. Also good.

  With this configuration, when a state in which the metal detection capability is reduced occurs, it is possible to more accurately grasp the cause of the decrease in the metal detection capability from the individual determination result and the combination determination result.

  In order to solve the above problems, a metal detector according to the present invention includes (6) the metal detector diagnostic device described in any one of (1) to (5) above. .

  In the metal detector according to the present invention, the diagnostic device having any one of the configurations described above can easily grasp the reduced state of the metal detection capability from the result of the comprehensive determination, and the problem such as false detection occurs in advance. Can be prevented. In addition, if the individual determination result or the combination determination result is used, it is possible to easily identify the factor that decreases the metal detection capability.

  According to the present invention, it is possible to provide a metal detector diagnostic device and a metal detector capable of accurately diagnosing a reduced state of metal detection capability and preventing the occurrence of problems such as false detection, It is possible to provide a diagnostic device for a metal detector and a metal detector that can easily identify a factor that lowers the metal detection capability.

It is a schematic block block diagram of the diagnostic apparatus of the metal detector which concerns on one Embodiment of this invention. It is a schematic block block diagram of the metal detector main body diagnosed with the diagnostic device of the metal detector which concerns on one Embodiment of this invention. It is explanatory drawing of an example of the joint determination performed with the diagnostic apparatus of the metal detector which concerns on one Embodiment of this invention. It is a flowchart which shows the outline flow of the diagnostic process performed with the diagnostic apparatus of the metal detector which concerns on one Embodiment of this invention.

  Hereinafter, preferred embodiments of the present invention will be described with reference to the drawings.

(One embodiment)
1 to 3 show a metal detector diagnostic apparatus and a metal detector in which a diagnostic process using the diagnostic apparatus is executed according to an embodiment of the present invention.

  First, the configuration will be described.

  As shown in FIG. 1, the metal detector of the present embodiment includes a metal detector body 10 and a diagnostic device 50 that executes a diagnostic process relating to the metal detection performance of the metal detector body 10.

  The metal detector main body 10 includes a conveyor 11 that conveys a workpiece W that is an object to be inspected in a predetermined direction, a detection unit 12 that has an inspection region R through which the workpiece W conveyed by the conveyor 11 passes, and the conveyor 11 and the detection unit. 12 and a detection control unit 14 for controlling the operation of 12.

  The workpiece W is an arbitrary product to be manufactured, for example, a mass-produced food packaged individually in a packaging material or in a predetermined number of units during transportation. It may be an indeterminate shape such as a flexible bag product enclosing an animal or the like.

  The conveyor 11 is not shown in detail, but an endless belt-like transport belt is wound around a plurality of parallel rollers, and a work transport path 11a that is substantially flat in a part of the travel section (usually the upper travel section). Is known. The conveyor 11 can move the workpiece W relative to the inspection region R by conveying the workpiece W placed on the workpiece conveyance path 11a in a predetermined direction at a preset conveyance speed. It is like that.

  The inspection region R is set in the movement path of the workpiece W conveyed by the conveyor 11, and the detection unit 12 detects a change in magnetic field (magnetic field fluctuation) due to the workpiece W passing through the inspection region R. Thus, a detection signal capable of determining whether or not a metal object such as a metal foreign object is included in the workpiece W is output.

  The metal object referred to here is a foreign substance made of metal or a foreign substance containing a metal component when detecting a foreign substance in the workpiece W, and made of metal or a metal when detecting a missing part in the workpiece W. It is a component that contains components. For convenience of explanation, in the following explanation, it is assumed that the metal object is a metal foreign object.

  The detection control unit 14 controls the operation of the conveyance of the workpiece W by the conveyor 11 and the detection of the magnetic field fluctuation by the detection unit 12, and determines the presence / absence of metal foreign matter in the workpiece W based on the output signal of the detection unit 12. It has become.

  As shown in FIG. 2, near the entrance of the inspection area R, for example, an optical work detection sensor 13 for detecting the entry of the work W into the inspection area R or the arrival at a predetermined position before entering is installed. .

  The detection unit 12 includes a signal generation unit 21 that generates a transmission signal having a preset amplitude and frequency, and a magnetic field generation unit 22 (magnetic field generation unit) that current-drives the transmission coil using a signal from the signal generation unit 21. And a magnetic field detector 23 composed of a motion detector or the like.

  Although not shown in detail, the signal generator 21 includes a reference signal generator that responds to the workpiece detection sensor 13, a timer for specifying a measurement period, a power amplifier, a tuning circuit, and the like. When passing through R, a transmission signal having a set frequency corresponding to the reference signal is generated to drive the transmission coil of the magnetic field generator 22.

  The transmission coil of the magnetic field generation unit 22 is disposed in the vicinity of the work conveyance path 11a of the conveyor 11, and when excited by current drive from the signal generation unit 21, an alternating magnetic field corresponding to the set frequency of the transmission signal. Is generated in the inspection region R.

  The magnetic field detection unit 23 is configured to detect a metal foreign object in a plurality of workpieces W in cooperation with the signal generation unit 21 and the magnetic field generation unit 22, and a pair of differentially connected receptions. It consists of a coil, a tuning circuit and an amplifier. The magnetic field detection unit 23 is adjusted so that the induced voltages of the pair of receiving coils are substantially balanced with respect to only the alternating magnetic field from the magnetic field generation unit 22 and the differential output therebetween is substantially zero.

  The magnetic metal that passes through the magnetic field attracts more magnetic flux in proportion to the magnitude of the magnetic flux density, and the nonmagnetic metal that passes through the magnetic field swirls in such a direction as to cancel the change in the magnetic flux density due to the movement. An electric current is generated and Joule heat is consumed. Therefore, when the workpiece W on the conveyor 11 passes through the inspection region R, the balanced state of the output between the receiving coils of the magnetic field detector 23 is lost.

  When the output balanced state between the two receiving coils is lost due to the movement of the workpiece W on the conveyor 11, the magnetic field detector 23 outputs a detection signal corresponding to the change in the magnetic field. This detection signal has a signal form in which a low-frequency signal component that changes due to the magnetic field passing through the workpiece W is superimposed on an AC signal component having a set frequency of the transmission signal corresponding to an alternating magnetic field from the magnetic field generation unit 22 side. .

  The detection signal of the magnetic field detection unit 23 is captured by the signal level measurement unit 24. The signal level measurement unit 24 is not shown in detail, but a pair of synchronous detectors, phase shifters, A band pass filter, an amplifier, an A / D converter, and the like are included.

  The pair of synchronous detectors of the signal level measuring unit 24 takes in a signal obtained by adjusting the phase of the reference signal for quadrature detection, and generates a detection output by removing a high-frequency component corresponding to a transmission signal from the detection signal. The signal level measurement unit 24 outputs a signal obtained by further applying noise removal and A / D conversion to the detection output to the metal presence / absence determination unit 26 and the detection control unit 14.

  The output of the quadrature detection is, for example, a detection signal in which the influence of a non-magnetic metal causing an external magnetic field change is larger as the change in magnetic flux density is larger, or a detection in which the influence of a magnetic metal causing an external magnetic field change is larger as the magnetic flux density is larger. Signal. Further, the detection signal of the low frequency component output from the signal level measuring unit 24 is a waveform of an envelope connecting instantaneous values of a predetermined phase position of the differential detection signal, and ¼ of the transmission signal period from the predetermined phase position. An envelope waveform connecting the instantaneous values whose phases are shifted by 90 degrees, that is, the phase is formed.

  On the other hand, the detection control unit 14 executes arithmetic processing according to a predetermined control program based on the detection signal of the detection unit 12 and the user's operation input from the operation unit 16, and the processing result is displayed as the signal generation unit 21 and the magnetic field. It outputs to the detection part 23, respectively.

  The detection control unit 14 has a microcomputer configuration including, for example, a CPU, a RAM, a ROM, and an I / O interface. The control program stored in the ROM is executed by the CPU while exchanging data with the RAM. Based on the signal from the signal level measurement unit 24 taken in via the I / O interface, detection processing described later is executed.

  Functionally, the detection control unit 14 includes an amplitude setting unit 31, a detection frequency setting unit 32, a magnetic field detection control unit 33, a storage unit 34, and a detection frequency selection unit 35 shown in FIG. Corresponding control program and setting information are built-in. In addition, the detection control unit 14 sets in advance whether or not it is required to execute a diagnostic process by the diagnostic device 50 in accordance with a diagnostic request operation input from the operation device 16 or an operating state of the metal detector main body 10. It has a function of making a determination based on the diagnosis request condition and outputting a diagnosis process request signal to the diagnosis device 50 when the diagnosis process is necessary.

  The amplitude of the generated signal of the signal generating unit 21 is set by the amplitude setting unit 31, and the set frequency of the transmission signal of the signal generating unit 21 is set by the detection frequency setting unit 32.

  Here, the amplitude setting unit 31, together with the signal generation unit 21, lowers the intensity level of the generated magnetic field of the magnetic field generation unit 22 from the first intensity level that is the magnetic field intensity level of the normal detection operation and the first intensity level. It can function as a magnetic field control means for switching to any one of the second strength levels. The detection frequency setting unit 32 has a function of setting the set frequency (generated signal frequency) of the signal generation unit 21 so as to define the generated magnetic field frequency of the magnetic field generation unit 22 during normal detection, and the magnetic field detection control unit 33. And has a function of setting a detection operating frequency (herein simply referred to as a detection frequency) of the magnetic field detection unit 23.

  Here, the first intensity level is a magnetic field intensity level in a range generated by the magnetic field generator 22 when performing a normal metal detection operation, and the second intensity level is generated from the signal generator 21 by a magnetic field generation. The transmission signal output to the unit 22 is stopped and the generation of the magnetic field by the magnetic field generation unit 22 is stopped, that is, the generated magnetic field strength is at a level that can be said to be about the normal residual value level.

  The magnetic field detection control unit 33 supplies a detection clock signal to the detector of the magnetic field detection unit 23 and, based on the set frequency information from the detection frequency setting unit 32, the frequency and phase of the detection clock signal (of the signal generation unit 21). It has a function of adjusting the phase difference with respect to the reference signal, and the detection operation frequency of the magnetic field detection unit 23 can be defined regardless of whether the magnetic field generation unit 22 is activated (whether the magnetic field is generated).

  The storage unit 34 is composed of a RAM or a rewritable nonvolatile memory device, and includes various detection information relating to metal detection and measurement results obtained by the signal level measurement unit 24, including a detection operation frequency during normal operation. Data can be stored and retained.

  The detection frequency selection unit 35 constitutes a measurement unit 36 together with the detection frequency setting unit 32, the magnetic field detection control unit 33, and the signal level measurement unit 24. In the measurement unit 36, the generated magnetic field of the magnetic field generation unit 22 is the first value. The electromagnetic noise in the inspection region R can be measured at a plurality of different detection operation frequencies of the magnetic field detection unit 23 in a state where the intensity level is 2.

  In addition, the detection frequency selection unit 35 cooperates with the detection frequency setting unit 32 and the magnetic field detection control unit 33 so that the electromagnetic noise level measured by the measurement unit 36 among the plurality of different detection operation frequencies is relatively small. Is selected, and the set frequency of the magnetic field generator 22 and the detection operation frequency of the magnetic field detector 23 corresponding thereto are variably set.

  By the way, the metal presence / absence determination unit 26 compares the detection signal amplitude level of each work W conveyed to the inspection region R with a predetermined threshold level, and whether or not the metal W is contained in the work W, that is, a product. As a determination means for determining whether the quality is acceptable or not by a known determination method, and outputting the determination result to the display unit 27. The metal presence / absence determination unit 26 also outputs a selection command signal for separating defective products from non-defective products to a selection unit 28 provided downstream of the inspection region R of the conveyor 11.

  On the other hand, as shown in FIG. 1, the diagnostic device 50 that executes diagnostic processing for the metal detector main body 10 includes an operation condition switching unit 51, an individual determination unit 52, a combination determination unit 53, and a comprehensive determination unit 55. ing.

  The operating condition switching unit 51 includes an information storage unit 51M that stores setting information of inspection conditions and setting information of diagnostic conditions set in advance on the metal detector main body 10 side, and at the time of diagnosis of the metal detector main body 10 The operation of the metal detector body 10 is switched based on the information stored in the information storage unit 51M, and the metal detector body 10 is operated in a plurality of types for a predetermined diagnostic process in cooperation with the detection control unit 14. It is designed to operate sequentially according to conditions.

  The individual determination unit 52 includes an information storage unit 52M that stores preset individual determination standards and past individual determination results. When the metal detector body 10 is diagnosed, the individual determination unit 52 operates for each type. Regarding the operation result of the metal detector main body 10 under the conditions, the allowable degree is individually determined.

  The combination determination unit 53 includes an information storage unit 53M that stores a predetermined combination determination standard and past combination determination results. When the metal detector body 10 is diagnosed, types of the plurality of types of operation conditions are included. Based on the operation result of the metal detector main body 10 in each operation condition, the operation results in the operation condition of two or more types are combined to create at least one combined operation result related to the metal detection performance, The combination determination for determining the allowable degree of the combined operation result is executed.

  The comprehensive determination unit 55 includes an information storage unit 55M that stores preset comprehensive determination standards and past comprehensive determination results. At the time of diagnosis of the metal detector body 10, at least the combination determination by the combination determination unit 53 is performed. In accordance with the result, a comprehensive determination for determining whether the metal detection performance of the metal detector main body 10 is good or not is executed.

  Specifically, the plurality of types of operation conditions for diagnostic processing in the operation condition switching unit 51 include at least a first operation condition and a second operation condition in which the operation conditions of the detection unit 12 are different.

  The first operating condition is that the detection unit 12 moves the test piece Tp for the detection sensitivity test of the detection unit 12 with respect to the inspection region R while the magnetic field generation unit 22 generates a magnetic field. This is an operating condition for detecting a change in the magnetic field in R. The test piece Tp for the detection sensitivity test mentioned here is, for example, a small-sized metal piece (iron or stainless steel) or a small-sized metal piece that can be detected when the sensitivity is about the catalog specification sensitivity of the metal detector body 10. It is a resin block.

  The second operating condition is an operating condition in which the detection unit 12 detects a change in the magnetic field in the inspection region R while operating the conveyor 11 without using the test piece Tp in a magnetic field generation state by the magnetic field generation unit 22. It is. Here, the change in the magnetic field in the inspection region R detected by the detection unit 12 is caused by factors other than the test piece Tp (for example, the influence of external electromagnetic noise, etc.) in the output balanced state between the receiving coils of the magnetic field detection unit 23. Appears as a result of failure.

  The plurality of types of operating conditions for diagnostic processing in the operating condition switching unit 51 are further the strength of the generated magnetic field in the magnetic field generating unit 22 of the detecting unit 12, the detection frequency in the magnetic field detecting unit 23 of the detecting unit 12, and the sorter 28. A plurality of operating conditions that differ from each other in at least one of the presence / absence of operation and the presence / absence of operation of the conveyor 11 may be included.

  The magnetic field generated in the magnetic field generator 22 is selected and set, for example, as one of multi-level intensity levels Lv0, 1, 2, 3, 4, and 5, and the detection frequency in the magnetic field detector 23 is, for example, Any one of a plurality of different detection operating frequencies fa, fb, fc, fd, and fe is selected and set.

  And the individual determination part 52 performs an individual determination about the multiple types of operation conditions including the following (1-1) thru | or (1-4), for example.

  (1-1) In a state where the conveyor 11 is stopped (conveyance speed is 0 m / min), the transmission output level corresponding to the intensity of the generated magnetic field in the magnetic field generating unit 22 is set to the standard Lv3, the generated magnetic field frequency Is set to 500 kHz, and the individual determination standard level corresponding to the upper limit value of the allowable level of the detected magnetic field (A / m) is set to 1000, for example, and the magnetic field reception performance in the magnetic field detector 23 is diagnosed.

  In this case, if the magnetic field detection signal level in the magnetic field detection unit 23 is 800, for example, the individual determination result is OK determination (good determination, normal determination).

  (1-2) With the conveying speed of the conveyor 11 set to, for example, 10 m / min, the transmission output level corresponding to the strength of the generated magnetic field in the magnetic field generating unit 22 is set to standard Lv3, the generated magnetic field frequency is set to 500 kHz, and allowed. The individual determination standard level corresponding to the upper limit value of the level is set to 1200, for example, and the environmental influence level which is the peak level of the detection signal of the magnetic field change in the inspection region R when the detection unit 12 is operated under the second operating condition described above. By measuring A, the magnetic field reception performance in the magnetic field detector 23 is diagnosed.

  In this case, if the detection signal level (environmental impact level A) in the magnetic field detection unit 23 is 1000, for example, the individual determination result is OK determination.

  (1-3) With the conveying speed of the conveyor 11 set to 10 m / min, the transmission output level corresponding to the strength of the generated magnetic field in the magnetic field generator 22 is set to standard Lv3, the generated magnetic field frequency is set to 500 kHz, and the detection sensitivity Based on the detection signal of the magnetic field detector 23 when the test piece Tp for testing is passed through the inspection region R by the conveyor 11, the detection signal corresponding to the test piece detection sensitivity capable of reliably determining and detecting the test piece Tp as a foreign object The level B is measured, and it is determined whether or not the detection signal level B corresponding to the test piece detection sensitivity exceeds the preset individual determination standard level of the detection signal level corresponding to the test piece detection sensitivity. Diagnose magnetic field reception performance.

  In this case, if the detection signal level B corresponding to the test piece detection sensitivity is, for example, 9000 or more, the individual determination result is OK.

  (1-4) In a state where the conveyor 11 is stopped and the generation of the magnetic field in the magnetic field generation unit 22 is stopped, at each of a plurality of different detection operation frequencies fa, fb, fc, fd, and fe of the magnetic field detection unit 23. The magnetic field detection unit 23 is operated, and the individual determination standard level corresponding to the upper limit value of the electromagnetic noise level is set to 800, for example, and the magnetic field reception performance in the magnetic field detection unit 23 is diagnosed.

  In this case, if the magnetic field detection signal level in the magnetic field detection unit 23 is, for example, 600 at any detection operating frequency, the individual determination result is OK determination.

  In addition, the individual determination part 52 does not use the result of executing the individual determination for a plurality of types of operation conditions such as (1-1) to (1-4) as the above-described OK and NG determination results. You may level as a stepwise permissible degree according to the operation result of metal detector main part 10 in operation conditions.

  Alternatively, the individual determination unit 52 executes individual determination for a plurality of types of operation conditions including, for example, the following (2-1) to (2-4).

  (2-1) With the conveyor 11 stopped and the generation of the magnetic field in the magnetic field generator 22 stopped, the magnetic field detector 23 has a plurality of different detection operation frequencies fa, fb, fc, fd, and fe, respectively. The magnetic field detection unit 23 is activated to diagnose the magnetic field reception performance of the magnetic field detection unit 23.

  In this case, if the magnetic field fluctuation detection signal level by the magnetic field detection unit 23 is less than a reference value or a reference magnification (for example, 1.2 times) set in advance with respect to the diagnosis result level at the time of factory shipment of the metal detector body 10, The individual determination result is OK determination. However, when the reference value or the reference magnification is exceeded due to the influence of external electromagnetic noise or the like, NG determination (defect determination, abnormality determination) is made.

  (2-2) With the conveyor 11 stopped, the transmission output level corresponding to the intensity of the generated magnetic field in the magnetic field generation unit 22 is set to the maximum Lv5, and a plurality of different detection operation frequencies fa to fe of the magnetic field detection unit 23 Then, the magnetic field detection unit 23 is operated to diagnose the magnetic field reception performance of the magnetic field detection unit 23.

  In this case, if the magnetic field fluctuation detection signal level by the magnetic field detection unit 23 is less than a predetermined reference value or a reference magnification (for example, 1.5 times) with respect to the noise allowable limit level at the time of factory shipment of the metal detector body 10. The individual determination result is OK determination. However, if the reference value or the reference magnification is exceeded due to the tuning frequency of the transmission side and the reception side or the difference in detection phase, an abnormality determination is made.

  (2-3) With the conveying speed of the conveyor 11 set to 10 m / min, the transmission output level corresponding to the intensity of the generated magnetic field in the magnetic field generator 22 is set to the maximum Lv5, and a plurality of different detections of the magnetic field detector 23 are performed. The magnetic field detector 23 is operated at each of the operating frequencies fa to fe, and the magnetic field reception performance in the magnetic field detector 23 is diagnosed.

  In this case, if the magnetic field fluctuation detection signal level by the magnetic field detection unit 23 is less than a predetermined reference value or a reference magnification (for example, 2.0 times) predetermined with respect to the noise allowable limit level at the time of factory shipment of the metal detector body 10. The individual determination result is OK, but if the reference value or reference magnification is exceeded due to the influence of belt or motor rotation, an abnormality determination is made.

  (2-4) With the conveying speed of the conveyor 11 set to 10 m / min, the transmission output level corresponding to the strength of the generated magnetic field in the magnetic field generator 22 is set to the maximum Lv5, and the test piece Tp for the detection sensitivity test is set. The magnetic field detection unit 23 is operated so as to obtain the detection signals of the magnetic field detection unit 23 when passing through the inspection region R by the conveyor 11 for a plurality of different detection operation frequencies fa to fe, and the magnetic field reception performance in the magnetic field detection unit 23 Diagnose.

  In this case, the detection signal level B corresponding to the test piece detection sensitivity capable of reliably determining and detecting the test piece Tp for detection sensitivity as a foreign object is measured, and the detection signal level B corresponding to the test piece detection sensitivity is measured by the metal detector. If the standard value of the main body 10 is less than a predetermined reference value or a reference magnification (for example, 2.0 times), the individual determination result is OK, but due to the influence on the sensitivity due to multiple factors. When the reference value or the reference magnification is exceeded, an abnormality is determined.

  As described above, when the individual determination unit 52 executes individual determination for a plurality of types of operation conditions including the above-described (2-1) to (2-4) operation conditions, the individual determination unit 52 includes a plurality of types of individual determinations. Is executed by the condition 1 determination unit 52a to the condition 5 determination unit 52e, for example.

  On the other hand, the combination determination unit 53 performs, as one combination determination, based on the individual determination results of the condition 1 determination unit 52a and the condition 2 determination unit 52b and data related to the determination (detected values of the magnetic field detection unit 23, etc.). In the 1-join determination unit 53a, for example, the following join determination is executed.

  (3-1) The peak level of the detection signal of the magnetic field change in the inspection region R obtained when the detection unit 12 is operated under the above-described second operating condition, obtained when the above-described individual determination (1-2) is performed. And the detection signal level B corresponding to the test piece detection sensitivity capable of reliably determining and detecting the test piece Tp obtained during the execution of the individual determination (1-3) as a foreign object. The signal level of the environmental influence level A and the detection signal level B corresponding to the test piece detection sensitivity (assuming that the signal level of the environmental influence level A is [A] and detection equivalent to the test piece detection sensitivity). The signal level of the signal level B is [B]) does not exist in the same range, the SN ratio ([B] / [A] value) is n times or more, or [A] and [B ] Is a gap M between It is no problem level determined by is ensured. Here, the margin M between [A] and [B] is at a level where there is no problem, for example, the maximum value of each signal level of [A] and [B] + (maximum value−minimum value) / m. And the range of the minimum value− (maximum value−minimum value) / m value are not present in the same range (n and m are arbitrary values).

  In this connection determination, there is a margin M equal to or greater than a preset margin Ma between the detection signal level B corresponding to the test piece detection sensitivity of the test piece Tp and the environmental impact level A in the inspection region R (M = | B-A |> Ma) is stably determined as a combined operation result including both operation effects at the time of individual determination of the detection signal level B corresponding to the test piece detection sensitivity and the environmental influence level A. It is.

  Further, as another combination determination, the combination determination unit 53 performs the first determination based on the individual determination results of the condition 3 determination unit 52c and the condition 4 determination unit 52d and data related to the determination (detection data of the magnetic field detection unit 23, etc.). In the two-join determination unit 53b, for example, the following join determination is executed.

  (3-2) Detection signal level [C] of the magnetic field detection unit 23 obtained when the above-described individual determination (1-1) is performed, and magnetic field detection obtained when the above-described individual determination (1-2) is performed. Whether the value of [D] / [C] exceeds or does not exceed n times is determined from information on the detection signal level [D] when the conveyor of the unit 23 is ON (n is an arbitrary value)).

  Then, the overall determination unit 55 determines whether the combination determination unit 53 has a combination determination result in the first combination determination unit 53a and the second combination determination unit 53b, or in addition to an individual determination result in the individual determination unit 52. Accordingly, for example, if all the combination determination results are OK (passed), the overall determination is also OK, or all the combination determination results of all the combination determination results and the specific individual determination result from the condition 5 determination unit 52e. If is OK, the overall judgment is also OK.

  The comprehensive determination unit 55 causes the display unit 27 to display and output information indicating whether the comprehensive determination result is OK or NG as first diagnosis information corresponding to the comprehensive determination result. Further, the comprehensive judgment unit 55 displays information for displaying main factors that reduce the margin M between the detection signal level B corresponding to the test piece test piece detection sensitivity and the environmental impact level A and the degree of influence for each factor. Is output by the display unit 27 as second diagnostic information corresponding to the result of individual determination or combination determination.

  The comprehensive determination unit 55 and the display unit 27 constitute diagnostic information output means according to the present invention. For example, the first diagnosis information displayed on the display unit 27 is information indicating that the metal detection performance is not good. In some cases, or whenever the first diagnostic information is displayed on the display unit 27, the second diagnostic information is displayed.

  Next, a procedure of diagnostic processing executed by the diagnostic device 50 will be described.

  FIG. 4 shows a schematic flow of a diagnostic processing program executed by the diagnostic device 50.

  As shown in the figure, first, it is determined whether or not a diagnostic processing request is issued from the detection control unit 14 to the diagnostic device 50 (step S11). If there is no diagnostic processing request (NO in step S11). This processing ends.

  On the other hand, if a diagnostic process request is issued from the detection control unit 14 to the diagnostic device 50 (YES in step S11), the operating condition switching unit 51 then changes the operating condition of the metal detector body 10 to the operating condition at the time of inspection. Or a process of switching from the previous operating condition to the current operating condition in the diagnostic process (step S12), and the operation control is performed under the operating condition after switching the metal detector body 10 by the operating condition switching unit 51 and the detection control unit 14. (Step S13).

  And the individual determination part 52 performs an individual determination process on the result of operating the metal detector main body 10 under the current operating conditions (step S14). The individual determination here is executed by any one of the condition 1 determination unit 52a to the condition 5 determination unit 52e corresponding to the current operation condition set by the operation condition switching unit 51 in accordance with the individual determination standard as the determination condition. The The individual determination result in the individual determination unit 52 is stored in the information storage unit 52M in association with the operation condition for each type (step S15).

  Next, it is determined whether or not the individual determination results necessary for executing any of the undetermined combination determinations are complete, and the undetermined combination determination is possible (step S16).

  At this time, if the necessary individual determination results are not complete and any combination determination is not possible (NO in step S16), the operating condition switching unit 51 sets the operating condition of the metal detector body 10 to the next operating condition. After executing the process of switching to (step S12), a series of processes (steps S13 to S15) up to the storage of the individual determination corresponding to the operating condition are executed again.

  When the necessary individual determination results are obtained and any undecided combination determination is possible (YES in step S16), the combination determination unit 53 then executes the combination determination (step S17). The combination determination result is stored in the information storage unit 53M (step S18).

  Next, it is determined whether or not the combined determination results necessary for executing the comprehensive determination are prepared, or whether or not the comprehensive determination is enabled by combining specific individual determination results in addition to the combined determination results (step). S19).

  At this time, if the necessary combination determination result is not complete or the specific individual determination result is not complete and comprehensive determination cannot be made (NO in step S19), the operating condition switching unit 51 causes the metal detector. A series of processes (steps S13 to S12) for switching the operating condition of the main body 10 to the next operating condition (step S12) and storing the result of the combined determination using the individual determination corresponding to the operating condition and the individual determination result. S18) is executed again.

  When the necessary individual determination results are obtained and comprehensive determination is possible (YES in step S19), comprehensive determination is then performed by the comprehensive determination unit 55 (step S20), and the comprehensive determination result is stored in the information storage unit. In addition to being stored in 55M (step S21), the first diagnostic information is displayed and output from the display unit 27 (step S22).

  Next, it is determined whether or not the result of comprehensive determination by the comprehensive determination unit 55 is NG (defect, failure) (step S23). If it is NG determination (YES in step S23), then the comprehensive determination unit 55. The second diagnostic information is displayed and output by the display unit 27 (step S24).

  On the other hand, if the result of the comprehensive determination by the comprehensive determination unit 55 is an OK determination (NO in step S23) or the second diagnosis information is displayed and output, the current process is terminated.

  Next, the operation will be described.

  In the metal detector diagnostic apparatus of the present embodiment configured as described above, when the metal detection capability of the metal detector main body 10 changes due to one or more specific factors, a plurality of these factors change. The individual judgment result obtained by the individual judgment unit 52 and the joint judgment result obtained by the joint judgment unit 53 for the operation under the various kinds of operation conditions are respectively changed, and the overall judgment for determining the quality of the metal detection performance according to the allowable degree. The result of the comprehensive determination in the determination unit 55 changes.

  Therefore, it is possible to easily grasp the reduced state of the metal detection capability of the metal detector main body 10 from the result of the comprehensive determination in the comprehensive determination unit 55, and it is possible that problems such as false detection in the metal detector main body 10 will occur. Can be prevented.

  Further, in the present embodiment, the environmental influence or the like in the usage state of the metal detector body 10 is increased, and the detection signal level B corresponding to the test piece detection sensitivity when the detection unit 12 is operated under the first operating condition and the detection are detected. If there is no margin between the environmental influence level A when the unit 12 is operated under the second operating condition, the individual determination result of the environmental influence level A and the individual determination result of the detection signal level B are OK determinations. In both cases, the result of the joint determination for determining whether there is a margin between them is NG determination, and the comprehensive determination result in the comprehensive determination unit 55 is NG determination. Therefore, before the deterioration of the metal detection capability progresses to such a level as to cause a problem such as a false detection, it is surely prevented that a problem such as a false detection occurs due to a reduction in the metal detection capability of the metal detector body 10. can do.

  Furthermore, in this embodiment, not only the result of the comprehensive determination in the comprehensive determination unit 55 but also the individual determination result in the individual determination unit 52, the combination determination result in the combination determination unit 53, and the data used for the determination. For example, as indicated by C1-C4 in FIG. 3, the display output from the display unit 27 can be displayed separately for each factor, or the main factor causing the failure can be displayed. Alternatively, as the second diagnostic information, the user can easily display and output whether there is a problem in the metal detection capability of the metal detector body 10, whether it is within an allowable range, and whether there is an improvement method. It may be possible to confirm.

  That is, according to the change in the metal detection capability of the metal detector body 10, the allowable degree as the individual determination result and the combination determination result respectively changes, and the quality determination result of the metal detection performance of the metal detector body 10 changes. The metal detection capability is reduced by the display output of the second diagnosis information, in addition to easily grasping the state of the metal detection capability reduction by the display output of the first diagnosis information corresponding to the result of the comprehensive determination. Factors can be easily identified.

  As a result, when there is no room for sensitivity to detect minute foreign objects against the increase of external electromagnetic noise and other environmental effects, it is easy to identify the factors that reduce the metal detection capability. Therefore, necessary maintenance can be performed accurately in a timely manner.

  In addition, in the present embodiment, the plurality of types of operation conditions include the intensity of the generated magnetic field in the magnetic field generation unit 22 of the detection unit 12, the detection operation frequency in the magnetic field detection unit 23 of the detection unit 12, and the operation of the sorter 28. Since the condition that is different from each other in at least one of the presence / absence and the presence / absence of the operation of the conveyor 11 is included, when the metal detection capability of the metal detector body 10 is lowered, the metal detection capability It is possible to more accurately grasp the cause of the decrease from the individual determination result and the combination determination result.

  Thus, according to the present embodiment, it is possible to provide a diagnostic device for a metal detector capable of accurately diagnosing a lowered state of metal detection capability and preventing the occurrence of problems such as false detection. It is possible to provide a diagnostic device for a metal detector that can easily identify a factor that lowers the detection capability of the metal detector body 10.

  In the above description of the embodiment, the diagnosis device 50 is configured separately from the metal detector main body 10. However, the diagnosis device 50 is connected to an existing metal detector control device and used separately. It is optional whether it is configured as a diagnostic apparatus or a diagnostic apparatus integrated with a metal detector having at least a self-diagnosis function built in the metal detector. Further, when the metal detector diagnostic device is configured separately, it may be configured as an external small diagnostic device, or connected to at least one metal detector control device via a network, You may comprise as a part of apparatus which monitors those operation | movement. In either case, the first diagnosis information corresponding to the result of the comprehensive determination and the second diagnosis information corresponding to the result of the individual determination or the combination determination are output.

  When configuring a metal detector with a built-in diagnostic device 50, the diagnostic device 50 can easily grasp the reduced state of metal detection capability from the result of comprehensive judgment, and prevent problems such as false detection from occurring. Self-diagnosis that can be performed becomes possible. In addition, by using the individual determination result and the combination determination result, it is possible to easily identify the factor that decreases the metal detection capability before problems such as erroneous detection occur.

  Further, in the above-described embodiment, when one specific individual determination result is used for the comprehensive determination, the comprehensive determination is performed in consideration of the specific determination result. The result of the specific individual determination result and information required for the determination may be used only for outputting the second diagnosis information. Therefore, a plurality of specific individual determination results may be used.

  Furthermore, the first combination determination unit 53a and the second combination determination unit 53b of the combination determination unit 53 are determined to combine using two individual determination results, respectively, but are combined by combining two or more individual determination results. You may judge. Needless to say, the metal detector according to the present invention is not limited to the magnetic field generation method or the magnetic field detection method as in the above-described embodiment. Further, when detecting the generated magnetic field of the magnetized metal object, a metal detector not equipped with magnetic field generating means may be used.

  As described above, the present invention can provide a metal detector diagnostic device and a metal detector capable of accurately diagnosing a lowered state of metal detection capability and preventing problems such as false detection. In addition, it is possible to provide a metal detector diagnostic device and a metal detector that can easily identify a factor in reducing metal detection capability, and the present invention provides a metal detector that performs metal detection using a magnetic field. The present invention is useful for general machine detectors and metal detectors having a diagnostic function equipped with the same.

10 Metal detector body 11 Conveyor (moving means)
11a Work conveyance path 12 Detection part (detection means)
13 Work detection sensor (entrance detection means)
14 Detection control unit (detection control means)
21 Signal Generator 22 Magnetic Field Generator 23 Magnetic Field Detector 27 Display Unit (Diagnostic Information Output Unit)
28 Sorting Unit 31 Amplitude Setting Unit 32 Detection Frequency Setting Unit 50 Diagnostic Device 51 Operating Condition Switching Unit (Operating Condition Switching Unit)
52 Individual determination unit (individual determination means)
52e Condition 5 determination unit (specific individual determination unit)
53 Coupling judgment unit (joint judgment means)
53a 1st combination determination part 53b 2nd combination determination part 55 Comprehensive determination part (Comprehensive determination means, diagnostic information output means)

Claims (6)

Detection means (12) for detecting a change in the magnetic field in the inspection region (R) through which the inspection object (W) passes and detecting metal in the inspection object, and detection control for controlling the operation of the detection means A metal detector diagnostic device for diagnosing a metal detector (10) comprising means (14),
In cooperation with the detection control means, an operation condition switching means (51) for operating the detection means under a plurality of preset operation conditions;
Individual determination means (52) for individually determining the allowable degree of the operation result under the operation condition for each type among the plurality of types,
Based on the operation result under the operation condition for each type of the plurality of types of operation conditions, at least one related to the metal detection performance by combining the operation results under the operation conditions for two or more types. A combination determination means (53) for creating a combined operation result and executing at least one of the combined determinations for determining an acceptable degree of the combined operation result;
Comprehensive determination means (55) for performing comprehensive determination for determining the quality of the detection performance of the metal according to the result of the individual determination and the result of the at least one combination determination. Detector diagnostic device. The metal detector includes a moving means (11) for moving the inspection object with respect to the inspection area,
The operating condition switching means is configured to move the test piece (Tp) for detection sensitivity test of the detecting means to the inspection area by the moving means as the plurality of types of operating conditions. And a second operating condition for detecting a change in the magnetic field in the inspection area by the detecting means while operating the moving means without using the test piece. Including
The coupling determination means, as the one coupling determination, detects a detection signal level (B) corresponding to a test piece detection sensitivity when the detection means is operated under the first operating condition; 2. The method according to claim 1, wherein it is determined whether or not there is a preset margin (M) between the peak level (A) of the detection signal of the change in the magnetic field when operating under an operating condition. Metal detector diagnostic device.   Diagnostic information output means (27, 55) is provided for outputting the first diagnostic information corresponding to the result of the comprehensive determination and the second diagnostic information corresponding to the result of the individual determination or the combination determination. 3. The diagnostic device for a metal detector according to claim 1, wherein the diagnostic device is a metal detector.   The diagnostic information output means displays second diagnostic information corresponding to a result of the individual determination or the combination determination when the first diagnostic information is information indicating that the metal detection performance is not good. The metal detector diagnostic device according to claim 3, wherein: This is because the detection means generates an alternating magnetic field having a set frequency included in a predetermined frequency range in the inspection region, and the inspection object passes through the alternating magnetic field. A magnetic field detector (23) for detecting a change in the alternating magnetic field at a detection operating frequency corresponding to the set frequency,
The plurality of types of operating conditions are at least one of the intensity of the generated magnetic field in the magnetic field generation unit of the detection unit, the detection operation frequency in the magnetic field detection unit of the detection unit, and the presence or absence of the operation of the moving unit. The metal detector diagnostic device according to any one of claims 2 to 4, wherein the diagnostic device is different from each other in one point.   A metal detector comprising the metal detector diagnostic device according to claim 1.

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