JP4188282B2 - Metal detector - Google Patents

Description

  The present invention relates to a metal detector for detecting a metal in an object to be inspected, particularly a metal detector suitable for detecting a metal foreign substance mixed in a product such as food conveyed on a conveyor, and further contains a metal in the product. The present invention relates to a metal detector that can also be used as an article inspection device for inspecting missing components and the like.

  Recently, there has been an increasing demand for improving the quality of distribution products to protect consumers. For example, there is a high demand for strengthening food hygiene management systems that conform to HACCP (Hazard Analysis Critical Control Point). Has been. Under such circumstances, metal detectors that detect metal foreign matters mixed in commodities such as food in production lines have been used more extensively than before.

  In conventional metal detectors, a magnetic field is generated so that a product conveyed on a conveyor passes through an alternating magnetic field having a predetermined frequency. Some detect the presence or absence.

  For example, as shown in FIG. 10, this type of metal detector includes a signal generator 1, a transmission coil 2, reception coils 3a and 3b, a detection unit 4, a control unit 5, and the like. A certain workpiece W passes through an alternating magnetic field generated from the transmission coil 2 in response to a signal generated by the signal generator 1 while being conveyed by the conveyor 6. The receiving coils 3a and 3b constitute a differential detector 3 that cooperates with the transmitting coil 2, and the outputs of the receiving coils 3a and 3b cancel each other in balance with respect to only the magnetic field generated by the transmitting coil 2, The output as the differential detector 3 becomes zero. When the workpiece W moves in the alternating magnetic field, the output balanced state of the receiving coils 3 a and 3 b is broken, and a differential detection signal is input to the detection unit 4. This differential detection signal becomes a signal that changes in accordance with the movement of the work 1 by removing the high-frequency signal component that changes in accordance with the frequency of the alternating magnetic field in the signal detection unit 4, noise removal by a filter, A / D conversion, etc. Applied to the control unit 5.

  The control unit 5 performs threshold determination using the signal amplitude of the differential detection signal as a threshold value with a predetermined voltage value or a predetermined magnification value with respect to the signal amplitude at the time of non-defective product inspection, and the amplitude of the detection signal exceeds the threshold value. When it is detected, it is determined that a metallic foreign object is mixed, and a signal indicating the determination result is output (for example, see Patent Document 1).

  In such a metal detector, a plurality of types of products are often inspected, and it is necessary to switch inspection conditions when performing inspections of different types. In such a case, for example, by operating a product type switching button on the operation panel, the product list data is read, and the product list is switched to another product type while scrolling the product list.

In addition, when inspecting new products, multiple products are repeatedly inspected to collect workpiece W transport speed, non-defective product inspection data, and defective sample (including small-sized metal foreign matter) inspection data. It is necessary to perform the accompanying setting work (see, for example, Patent Document 2).
Japanese Patent No. 2574694 Japanese Utility Model Publication No. 5-24069

  However, with conventional metal detectors, when registering new varieties, repeated inspections are required to set parameters using good product samples and defective samples in the operating environment. Therefore, the detection sensitivity has not been effectively used to identify the registration information of the resulting varieties.

  For example, the same type may be individually inspected depending on the stage of the entire manufacturing process, etc., or the unit at the time of shipment (for example, a box or pack containing 1 dozen). It is difficult for a user who only inputs identification information such as a product name on the switching screen to distinguish between products having the same / similar product name. In addition, when scrolling the screen display while holding the product list data, if you do not have the display hierarchy to select a specific product and display its details from the state in which you can refer to the name of the product that has already been set, The setting conditions such as the metal detection sensitivity cannot be displayed, and the operation may be complicated.

  The present invention has been made to solve such problems of the prior art, and by displaying information on typical setting conditions of each product type during display of the product type list, product type switching work, product type registration, etc. The purpose is to reduce the operation load or manual input work.

In order to achieve the above object, the metal detector of the present invention has a detection means for outputting a detection signal for detecting a metal in the inspection object for a plurality of types of inspection objects, and threshold determination based on the detection signal judging means for judging contamination of the metal by a setting unit for setting for each variety of the inspection object configuration parameters relating to the detection of said detecting means, when inspecting the inspection object on the basis of the setting parameters the estimated sensitivity managing means for specifying a detection sensitivity which is represented by the magnitude of determinable metallic foreign matter contamination of the metal by the determination unit, a previously inputted identification information for identifying the type of the said object to be inspected in the said sensitivity corresponding to varieties of the object to be inspected, a list information generation means for generating information data varieties list containing, based on the information data generated by the list information generation means The serial varieties list is obtained and a display means for displaying a predetermined display format.

  With this configuration, identification information of multiple types of inspected items and estimated detection sensitivity for each type of inspected items are displayed in a predetermined display format as the type list information. Even if only an input is made, each product name can be obtained as visual information together with the detection sensitivity obtained as a result of the setting at the time of registration, without moving from the display list of the product list to another display layer. . The predetermined display format here may be, for example, a scroll display format in a display area from one line to a plurality of lines, or may be a type in which product list information is displayed collectively. The list information is not necessarily limited to the table format, but may be a graph format including a plurality of types of information.

In the metal detector of the present invention, the estimated sensitivity management means specifies the detection sensitivity for each of a plurality of detection sensitivity modes having different setting parameters for the inspection object of each type, and the specified detection wherein determining either sensitivity mode of the detection sensitivity mode based on the sensitivity, the list information generation means, before and Ki識 specific information, before dangerous out sensitivity information varieties list including the detection sensitivity mode It should generate data.

  With this configuration, a plurality of detection sensitivity modes are set for each type of inspected object, and even when the user inputs only about the name of the type at the time of registration, the identification information of the multiple types of inspected objects and the inspected objects of each type The estimated detection sensitivity and sensitivity mode are displayed in a predetermined display format. Therefore, without moving from the display list of the product list to another display layer, each product name can be obtained as visual information along with the detection sensitivity and its sensitivity mode obtained as a result of the settings at the time of registration. The user can select a desired sensitivity mode manually.

In the metal detector of the present invention, furthermore, in accordance with the second display mode to hide the first display mode and before dangerous out sensitivity to display the previous danger out sensitivity varieties of the object to be inspected comprising a display mode switching means for switching, the list information generation means generates information data varieties list including determination level indication information indicating the set threshold value in the determination means for the corresponding varieties to the second display mode It is preferable to adopt a configuration to do so.

  With this configuration, even in an operation mode in which it is not necessary to display the detection sensitivity such as the diameter of a metal foreign object and not to detect foreign objects, the judgment reference level in that mode can be obtained as visual information. Registration and switching with different criteria can be easily performed.

  According to the present invention, when displaying the list of types, the identification information of the inspection items of a plurality of types and the estimated detection sensitivity for the inspection items of each type are displayed in a predetermined display format. Even if it is not input, each product name can be obtained as visual information together with the detection sensitivity obtained as a result of setting at the time of registration without moving to another display layer in the display list of the product list. As a result, it is possible to reduce the operation burden associated with the product type switching operation and the like, and to eliminate the troublesomeness in product type identification.

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

  1-9 is a figure which shows schematic structure of the metal detector based on the 1st Embodiment of this invention.

  First, the configuration will be described.

  In FIG. 1, the metal detector 10 has a housing 11, and an inspection conveyor 12 is inserted into a hole 11 a formed on the lower side of the housing 11. The conveyor 12 is means for conveying the workpiece W, which is an object to be inspected, in the direction of the thick arrow in FIG. 1 (rightward in the drawing) at a predetermined conveyance speed, and the conveyance speed is variable according to the conveyance speed of the production line of the workpiece W. Is set. Between the upper surface of the normal conveyance direction conveyor 12 and the housing | casing 11, it becomes the test | inspection area | region 14 for inspect | inspecting the workpiece | work W in the middle of the conveyance, and the entrance side (upstream side of a normal conveyance direction) of the test | inspection area | region 14 is carried out. For example, an optical workpiece detection sensor 15 for detecting the entry of the workpiece W into the inspection area is installed.

  The workpiece W is an arbitrary product manufactured in plural, for example, a mass-produced food packaged individually in a packaging material or in a predetermined number of units during transportation, and is a regular product such as a boxed product, It does not matter whether it is an indeterminate shape such as a flexible bag product enclosing a fluid.

  On the upper front side of the housing 11, there are provided an operation input unit 16 for operation input by a user, a display 17 for performing display for the operation, operation state display, abnormality notification, and the like. . The conveyor 12 is configured to move the workpiece W in the direction opposite to the arrow in FIG. 1 at the time of setting and return the workpiece W to the inspection start position.

  As shown in FIG. 2, a signal generator 21, a transmission coil 22, reception coils 23 a and 23 b, a detection unit 24, A / D converters 27 a and 27 b, and a control unit 30 are provided inside the housing 11. Yes.

  The signal generator 21 generates a transmission signal C having a predetermined frequency, and current-drives the transmission coil 22 via a current amplifier (not shown). Further, the transmission coil 22 is disposed in the vicinity of the conveyance path of the conveyor 12, and when excited by current drive from the signal generator 21, an alternating magnetic field having a predetermined intensity corresponding to the frequency of the transmission signal C is generated in the inspection region 14. It is supposed to be generated. The transmission coil 22 and the signal generator 21 constitute a magnetic field generation circuit unit.

  The receiving coils 23a and 23b are composed of a similar pair of coils arranged so as to intersect with the magnetic flux generated from the transmitting coil 22 and coupled in opposite phases to each other, grounded at one end facing each other and detected at the other end. Connected to the unit 24. These receiving coils 23a and 23b constitute a differential detector 23 (detecting means) for detecting a metal in the workpiece W with respect to a plurality of workpieces W (inspection object) in cooperation with the transmitting coil 22. The frequency of the alternating magnetic field from the transmission coil 22 can be variably set to any one of a plurality of frequencies by the control unit 30 described later, and the differential detector 23 is required for the alternating magnetic field of each set frequency. Detection sensitivity.

  In response to the influence of the alternating magnetic field from the transmitting coil 22, a voltage corresponding to the fluctuation of the magnetic field is induced in the receiving coils 23a and 23b, but only the alternating magnetic field from the transmitting coil 22 is received in reverse phase connection. The voltage outputs of the coils 23a and 23b are equally balanced, and the output as the differential detector 23, which is the difference between the induced voltages of the coils 23a and 23b, becomes zero. For this reason, for example, the other ends of the receiving coils 23a and 23b are coupled via a variable resistor (not shown) for balance adjustment, and connected to the detector 24 from the midpoint of the variable resistor.

  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, for example, as shown in FIG. 2, when some metallic foreign matter contained in the product on the conveyor 12 passes through the magnetic field generated by the transmission coil 22, as shown in FIGS. 3 (a) to 3 (c). The magnitude relationship between the induced voltages Va and Vb of the receiving coils 23a and 23b changes in accordance with the position of the metal foreign object attracting the magnetic flux, and the output equilibrium state between the receiving coils 23a and 23b is greatly lost. Also, when only products that are mainly non-magnetic materials pass through the magnetic field generated by the transmission coil 22, it is not as noticeable as when it contains metal due to the effects of its components, moisture, packaging materials, etc. The balanced state of the output between the coils 23a and 23b is lost.

  The receiving coils 23a and 23b output the differential detection signal Sd corresponding to the change in the magnetic field when the output balance between the receiving coils 23a and 23b is lost due to the movement of the product on the conveyor 12 as described above. . The differential detection signal Sd has a frequency of the transmission signal corresponding to an alternating magnetic field from the transmission coil 22 side (the phase is substantially reversed with respect to the transmission signal), and a high-frequency signal component of the workpiece W A modulated signal form is formed by superimposing low-frequency signal components whose amplitude and phase change due to constant speed movement, and can be represented by a signal waveform as shown in FIG. 4, for example.

  The detection unit 24 includes a pair of mixers 24a and 24b, bandpass filters 25a and 25b, and phase shifters 26a and 26b. The differential detection signals from the differential detector 23 are parallel to the mixers 24a and 24b, respectively. Is input. These mixers 24a and 24b are respectively connected to phase shifters 26a and 26b for shifting the phase of the input signal by a set phase shift amount. The phase shifter 26a is configured to transmit the transmission signal from the transmission signal generator 21. The phase is shifted by the set phase shift amount and supplied to the mixer 24a. In addition, the phase shifter 26b shifts the phase of the signal generated by the phase shifter 26a by 90 degrees, thereby 90% of the high-frequency signal component of the differential detection signal that is induced and output from the differential detector 23. High-frequency signals having different degrees of phase are generated and supplied to the mixer 24b.

  The mixer 24a synthesizes the high-frequency signal from the phase shifter 26a and the differential detection signal Sd from the differential detector 23 and outputs the resultant signal to the bandpass filter 25a. Similarly, the mixer 24b synthesizes the high-frequency signal from the phase shifter 26b and the differential detection signal Sd from the differential detector 23 and outputs the synthesized signal to the bandpass filter 25b.

  Here, the mixing of the input by the mixers 24a and 24b varies depending on the amount of phase shift, but for example, based on the input signal from the phase shifters 26a and 26b, the moment when the change in the magnetic flux density becomes maximum (phase 0 degree). On the other hand, the larger the magnetic flux density change, the greater the influence of the non-magnetic metal that consumes Joule heat and causes the external magnetic field change, and the moment when the magnetic flux density itself is almost maximum (the moment when the amplitude of the magnetic field waveform is maximum; On the (90 phase) side, the larger the magnetic flux density, the more the magnetic flux is attracted to generate a signal having a greater influence of the magnetic metal causing an external magnetic field change.

  The bandpass filters 25a and 25b are filters that extract only the low-frequency signal component that changes in accordance with the movement of the work W from the modulated signals synthesized by the mixers 24a and 24b, and also remove the high-frequency component noise. It has characteristics. The low-frequency component detection signals output from the bandpass filters 25a and 25b are an envelope waveform connecting instantaneous values of the predetermined phase position of the differential detection signal Sd, and 1 / of the transmission signal period τ from the predetermined phase position. An envelope waveform (waveforms X and Y shown in the figure) connecting the instantaneous values whose phases are shifted by 90 degrees, ie, 90 degrees, is formed.

  The outputs of both bandpass filters 25a and 25b are converted from analog to digital detection signals by the A / D converters 27a and 27b, respectively, and then taken into the control unit 30.

  The control unit 30 has a microcomputer configuration including 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. The detection signal taken in via the / O interface is processed.

  As shown in the functional block diagram of FIG. 2, the control unit 30 includes a setting unit 31, a memory unit 32, a feature data creation unit 33, an estimated sensitivity management unit 34, a determination unit 35, a display mode switching unit 36, and list information generation. The functions of the unit 37 and the display processing unit 38 are realized.

  The setting unit 31 includes the size (for example, length) and the conveyance speed of the workpiece W of each type, the generated signal frequency of the signal generator 21, the phase shift amount of the phase shifter 26a, the filtering bands of the bandpass filters 25a and 25b, etc. Various setting parameters related to the operation of the metal detector 10 are setting means for setting partly manually for each type of workpiece W (inspection object) and others automatically. When registration items are input from the operation input unit 16, new setting parameter group data corresponding to the product type is created for each product type specified by the product type number. Note that the length of the workpiece W and the conveyance speed are conditions for determining the capture time and interval of the detection signals X and Y, the filtering bands of the bandpass filters 25a and 25b, and the like. The signal frequency generated by the signal generator 21 is a parameter that is selected according to the type of metal to be detected and the material of the workpiece W (such as contents and packaging material). Further, as apparent from the fact that the detection signal X is specified by the instantaneous value of the predetermined phase position corresponding to the phase shift amount of the phase shifter 26a, the waveform amplitudes of the detection signals X and Y differ depending on the phase shift amount. It will be. Therefore, the phase shift amount of the phase shifter 26a is a parameter that determines the detection sensitivity of the metallic foreign matter mixed in the workpiece W.

  The set parameters set here are classified for each type of work W and stored in the parameter storage area 32 a of the memory unit 32. That is, the memory unit 32 is a data storage unit that stores data of setting parameters relating to the detection of the workpieces W of each type together with the type numbers and other identification information of the workpieces W of a plurality of types. The parameter storage area 32a of the memory unit 32 is a rewritable memory area, and can be configured by, for example, a nonvolatile semiconductor memory element, a memory disk, a hard disk, or the like that can be additionally written or rewritten.

  When the workpiece W is detected by the workpiece detection sensor 15, the feature data creation unit 33 samples the data of the detection signals X and Y every predetermined time for a certain period of time under the set capturing condition, and the sampled detection Based on the instantaneous values x and y of the signals X and Y, a coordinate point (x, y) having the instantaneous values x and y as coordinate components in the X-axis direction and the Y-axis direction while the workpiece W is passing through the magnetic field is X Data D of Lissajous's figures drawn on the -Y plane is created and stored in the inspection data storage area 32d of the memory unit 32.

  As shown in FIG. 4, these Lissajous figures are substantially symmetrical with respect to the origin O, and have coordinates at the furthest distance from the origin O. For example, the Lissajous figure Hn in the figure is the coordinates of the vertex Qn. It can be characterized by (Xm, Ym). Alternatively, the coordinate data of the vertex Qn may be converted into polar coordinates and characterized by coordinates (r, θ). Here, r is the distance from the origin O of the vertex Qn, and θ is the angle (tan θ = Ym / Xm) formed by the line segment QO and the X axis. Therefore, the feature data creation unit 33 may create such feature data D when setting parameters for each product type.

  When a sample of a non-defective workpiece W is inserted and passed in an alternating magnetic field, the Lissajous figure drawn by the coordinate point becomes, for example, an approximately 8 shape as indicated by Hg in FIG. In this case, the Lissajous figure drawn by the coordinate points has a long and narrow figure of 8 as shown by Hn in FIG. As described above, the Lissajous figure obtained based on the detection signals X and Y has a different inclination (major axis direction) depending on whether or not a foreign metal is included in the detection target. In addition, the Lissajous figures obtained for metallic foreign objects of the same type and different diameters have similar shapes, the inclinations of which are almost the same, and the distance from the origin of the apex differs depending on the diameter of the foreign objects.

  At the time of setting by the setting unit 31, first, based on the data of the Lissajous figure Hn and Hg when using the non-defective work sample and the metal foreign object sample of the minimum diameter, a plurality of candidate values for the angles θd of different detection phases are set, With respect to the angle θd of each candidate value, a point having the maximum distance from the straight line A intersecting the origin O is identified among the points on the Lissajous figure, and the ratio α = the maximum distances Ln and Lg (see FIG. 5). A sample sensitivity setting process is performed in which the angle θd of the candidate value that maximizes Ln / Lg is adopted as the optimum setting value θi.

  In the present embodiment, at the time of setting by the setting unit 31, sample sensitivity setting processing associated with a non-defective sample of the workpiece W is performed for a plurality of metal foreign material samples having different diameters d, and inspection results for the different diameter metal foreign materials 1 to n are performed. Data D (1) to D (n) are collected. And the ratios α1 to αn obtained by the sample sensitivity setting process using these different diameter metal foreign objects 1 to n (corresponding to the ratio of the metal foreign object detection signal to be acquired and the detection signal of the non-defective work sample corresponding to noise) , Hereinafter, also simply referred to as the S / N value) is stored in the parameter storage area 32a of the memory unit 33 in association with the diameters d1 to dn and the product type (product type) of the metal foreign object.

  The values of the S / N values α1 to αn associated with the sizes (diameters) of these metal foreign objects can be graphed as shown in FIG. 6, for example, and the smaller the α value, the smaller the metal foreign object can be detected. It can be seen that the detection characteristic becomes sensitivity. Therefore, when setting the detection sensitivity, by selecting a specific S / N value α, the diameter of the detectable metal foreign object can be specified. Conversely, the size (for example, diameter) of the metal foreign object to be detected can be determined. By specifying, a specific S / N value α required can be determined.

  When there is inspection result data D (1) to D (n) for the different diameter metal foreign matter samples 1 to n collected in advance as described above, the estimated sensitivity management unit 34 selects a good product sample in the use environment. The sensitivity characteristic of the metal detector 10 required for the inspection of the product is estimated and managed only by the inspection used, and data of the Lissajous figure obtained by using a non-defective product sample (instead of the above-mentioned Hg) Each metal foreign object is based on the value of the distance Ln obtained from the inspection result of the user product) and the inspection data D (1) to D (n) (inspection result of each metal foreign object sample corresponding to the aforementioned Hn). The S / N value α is calculated for the diameter and stored in the inspection data storage area 32 d of the memory unit 32. The estimated sensitivity management unit 34 also calculates the minimum α (= Ln / Lg) that can be set based on the product measurement data (for example, the Lg) when registering a new product, and the minimum mixed metal corresponding thereto The size of the foreign object can be specified.

  The estimated sensitivity management unit 34 estimates the detection sensitivity for each type of workpiece W based on the preset parameters for the different-diameter metal foreign material samples 1 to n, and stores the estimated detection sensitivity in the data in the memory unit 32. This is an estimated sensitivity management means stored in the area 32d.

  The estimated sensitivity management unit 34 further collects data of a plurality of detection sensitivity modes having different frequencies of the alternating magnetic field for each type of work W, and determines one of the detection sensitivity modes. The management is adopted to adopt this as the default sensitivity mode. The sensitivity mode can be represented by, for example, a straight line with an upward slope as shown in FIG. 6, but it can also be a characteristic line such as a curved line with an upward slope or a slightly bent shape. Therefore, when the plurality of detection sensitivity modes are such a plurality of characteristic lines, the detection mode having the smallest metal foreign object diameter that can be detected among the points where the characteristic lines of the plurality of modes intersect the threshold level for foreign object detection (in FIG. The characteristic line that comes to the far left is the preferred sensitivity mode. Since there are sensitivity characteristics such as a curved shape and a slightly bent shape, in this embodiment, it is possible to manually select and set to an arbitrary mode.

  First, the determination unit 35 sets a threshold value for performing a pass / fail determination based on an allowable metal foreign material diameter (size) set or inputted in advance or an unacceptable metal foreign material diameter value. The threshold value here is smaller than the specified metal foreign material diameter (for example, d2), that is, the metal foreign material diameter dr (d1 <dr <d2) on the high sensitivity side or the S / N value αr (α1 <αr) corresponding thereto. <Α2).

  Based on the threshold dr or αr, the determination unit 35 calculates the S / N value α from the inspection data of each workpiece W manufactured on the actual manufacturing line and transported to the inspection region 14, and compares this with the threshold αr. Refer to whether or not metal foreign matter having an unacceptable particle size is mixed, that is, whether the product is acceptable or not, or the type of metal foreign matter (particularly magnetic metal or nonmagnetic metal) and The size is specified, and a signal indicating the pass / fail judgment result or the type and size of the metallic foreign object is output. That is, the determination unit 35 determines whether or not metal foreign matter is mixed in the workpiece W by threshold determination based on the detection signal, and outputs a signal indicating the determination result when it is determined that metal foreign matter is mixed. It is a determination means that can.

  The display mode switching unit 36 selects a first display mode in which the estimated detection sensitivity is displayed on the display unit 17 (display means) and a second display mode in which the estimated detection sensitivity is not displayed. The display mode switching means switches according to the type of the product. Here, the first display mode is a display mode for varieties that perform normal metal detection, and the second display mode does not perform normal metal detection, and does not perform normal metal detection (component material, packaging material, liquid to be included). This is a display mode when performing omission etc.).

  Based on the data stored in the memory unit 32 (data storage unit), the list information generation unit 37 identifies the plurality of types of workpiece W (inspection object) identification information and the estimated detection sensitivity of each type of workpiece W. The list information generating means for generating the information data of the product type list including the information information is processed by the display processing unit 38 and displayed on the display unit 17 in the form as shown in FIG. The

  The display processing unit 38 executes image data processing for displaying a list of product types in a predetermined display format based on the information data generated by the list information generating unit 37 and supplies the image data to the display unit 17.

  When the first display mode is set by the display mode switching unit 36, the list information generating unit 37 identifies the identification information of a plurality of types of workpieces W, the estimated detection sensitivity and sensitivity of the workpieces W of each type. Information data of a list of types including modes is generated. Furthermore, when the second display mode is set by the display mode switching unit 36, the list information generating unit 37 performs identification information for a plurality of types of workpieces W and a pass / fail determination for the types of workpieces W. Information data of a product list including determination level instruction information corresponding to the threshold value is generated.

  The information data of the product list is partially displayed in a predetermined format by the display unit 17 when an operation input for specifying product switching is made to the operation input unit 16, and further scroll operation and page movement to the operation input unit 16 are performed. The display portion (referenced area) is moved by the operation. The display format of the product list information data may be such that, for example, the product list information that can be scroll-displayed is partially displayed in a display area from one line to a plurality of lines, and the entire product list is referred to by scrolling. The information may be displayed collectively. The list information is not necessarily limited to the table format, but may be a graph format including a plurality of types of information.

  As shown in FIG. 7, the display screen 50 of the display device 17 is provided adjacent to the operation input unit 16. Further, the operation input unit 16 includes a product type switching key 61, a menu key 62, a return key 63, an arrow key 64 for cursor movement / page switching, a return key 65 for determining a selection item, an operation command key 66, and a stop command key. 67 etc. are provided.

  Hereinafter, the generation and display contents of display information on the display screen 50 will be described together with the operation of the metal detector 10 having the above configuration.

[When setting]
When the metal detector 10 is set, when the user presses the menu key 62, a menu screen (details not shown) having selection items such as auto setting, detection sensitivity (level) change, article influence display, and statistics menu is displayed. First, auto setting is selected, and a non-defective sample of the workpiece W is measured a plurality of times, thereby making initial settings necessary for machine operation.

[Normal operation mode]
During normal operation of the metal detector 10, the operation screen as illustrated in the upper part of FIG. 7 is displayed on the display screen 50.

  As shown in the figure, during normal operation, product number 71, product name 72, judgment result OK (non-defective product / acceptable) / NG (defective product / non-acceptable) character 73, total number of workpieces 74 were counted. The number of NG products 75, a character 76 indicating that the operation is in a stopped state or the like are displayed, and an NG character 73 is displayed when mixing of a metal foreign object into the workpiece W is detected.

[Product switching mode]
On the other hand, when the production of the planned number of workpieces W is completed and switching to another type is performed, the type switching key 61 of the operation input unit 16 is operated, and a type list display screen for switching types is displayed. Is done.

  As shown in FIG. 8, the product list display screen includes a product number 81, a product name 82 which is an element for specifying the product name, an operation mode display symbol 83, and an estimated detection sensitivity 84 of iron (Fe) metal foreign matter. , Estimated detection sensitivity 85 of non-ferrous metal stainless steel (for example, SUS304) metallic foreign matter, a plurality of detection sensitivity modes (“A”, “ A symbol display 86 is displayed to indicate which mode is indicated (indicated by “B”, “C”, or “D”). In the symbol display 86 of the detection sensitivity mode, the left side of the hyphen (-) indicates the iron-based transmission signal frequency, and the right side indicates the non-ferrous transmission signal frequency. The four detection sensitivity modes indicated by “D” are set in order of frequency. Among the four sensitivity modes, for example, A is the highest frequency of the alternating magnetic field from the transmission coil 22 side, and D is the alternating from the transmission coil 22 side. The frequency of the magnetic field is the lowest.

  When this screen is displayed, the control unit 30 determines whether or not the type registration status has reached the registration setting stage and determines the display contents. Thus, when the product registration status has not reached the registration setting stage, the product name 82 and the estimated detection sensitivities 84 and 85 are not displayed (see the top column in FIG. 8A).

  Further, even when the type registration status has reached the registration setting stage, the operation mode display symbol 83 becomes a question mark symbol “?” When the auto setting has not yet been selected (FIG. 8B). (See (c) uppermost column), when the status of product registration has already been registered, the asterisk symbol “*” (see the uppermost column in FIG. 8D) indicates that the conveyor mode for executing only the conveyor conveyance is designated. It can be switched to the exclamation point symbol “!” (Not shown).

[Display mode switching]
By the way, in the product list display screen displayed at the time of product type switching, the first display mode for displaying the estimated detection sensitivity by the display unit 17 is set or the estimated detection sensitivity is not displayed. Depending on whether the display mode is set, different displays are made for each product type. In other words, for products that perform normal metal detection in which the first display mode is set, the estimated detection sensitivity is displayed, but normal metal detection is not performed, and components (packaging material, content flow, etc.) are not displayed. For the types that are missing), determination level instruction information indicating the degree of severity of the pass / fail determination regarding the work W of the type, for example, the threshold value, a value indicating the threshold level, or a level meter Is displayed.

More specifically, for example, in the case where the status of product type registration is the second display mode and the missing product check type for inspecting the lack of metal components among the components of the work W,
As shown in the bottom column of FIGS. 8A to 8D, instead of displaying the estimated detection sensitivities 84 and 85, a black square symbol “■” indicating that only the determination result is displayed. 88 and a threshold value 87 for performing a pass / fail judgment is displayed.

[Change sensitivity]
When changing the detection sensitivity, first, a sensitivity change key (not shown) of the operation input unit 16 is operated, or an appropriate one of the operation input unit 16 is displayed on the menu screen, the product type switching screen, or the operation state display screen. By operating the key and moving the cursor with an arrow key, for example, one of the display portions of the estimated detection sensitivities 84 and 85 is selected, and the selection including the metal species is confirmed with the return key.

  As a result, as shown in FIG. 9, as the current operation mode setting conditions, metal foreign matter types 91a and 91b (Fe and SUS in the figure), minimum foreign matter size values 92a and 92b indicating detection sensitivity, and level meter Operation bars 93a and 93b of the product-like product influence degree (the ratio of the product influence to the foreign object detection signal; the black portion in the figure is the product influence), and a threshold value for determining the mixed metal in consideration of the product influence 94a and 94b are displayed.

  The user specifies the metal foreign matter type 91a or 91b by changing and inputting the numerical value 92a, 2b or the threshold value 94a or 94b of the minimum foreign matter size indicating the detection sensitivity, or by operating the operation bar. Sensitivity is changed by changing 94a or 94b.

  As described above, in the present embodiment, not only the identification information 81 such as the identification number 81 and the item name 82 of a plurality of types of workpieces, but also the estimated detection sensitivity for each type of workpiece W is included as the type list information. Displayed in a predetermined display format. Therefore, even if the user inputs only about the product name at the time of product type registration, each product name is visually displayed together with the detection sensitivity obtained as a result of the setting at the time of registration without moving from the product list display layer to another display layer. It can be obtained as information. As a result, even if the product type is confusingly similar to the product name, it can be easily identified by associating it with the setting contents represented by the detection sensitivity.

  Further, for each type of work W, a plurality of different detection sensitivity modes are set according to the frequency of the alternating magnetic field from the transmission coil 22, and as the type list information, the identification information of the plurality of types of work W and the type of work W The estimated detection sensitivity and sensitivity mode are displayed in a predetermined display format, so that each model name can be obtained as a result of setting at the time of registration without moving from the display list of the product list to another display layer. Both the detected sensitivity and its sensitivity mode can be obtained as visual information. In some cases, a preferred sensitivity mode can be selected manually.

  In the metal detector 10 of the present embodiment, a first display mode for displaying the estimated detection sensitivity and a second display mode for not displaying the estimated detection sensitivity are further selected according to the type of the workpiece W. Since the display mode switching unit 36 for switching is provided, and the list information generating unit 37 displays the determination level instruction information 87 indicating the threshold value for performing the pass / fail determination for the work W of the specific type corresponding to the second display mode. Even in an operation mode that does not require detection of foreign matter detection and detection sensitivity such as metal foreign matter diameter, the judgment reference level in that mode can be obtained as visual information, and the pass / fail judgment criteria for the same product can be obtained. Different registrations and switching can be easily performed.

  As described above, according to the present invention, when displaying a list of varieties, the identification information of a plurality of varieties of inspected items and the estimated detection sensitivity of each varieties of inspected items are displayed together. Even if it is not input, each product name can be obtained as visual information together with the detection sensitivity obtained as a result of the setting at the time of registration without moving to another display layer in the display list of the product list. Only the metal detector suitable for detecting the metal foreign matter mixed in the product conveyed by the conveyor has the effect of reducing the operational burden associated with the switching work and the like and eliminating the troublesomeness in identifying the product type. In addition, the present invention can also be applied to an article inspection apparatus that inspects for missing components or the like containing a metal in a product.

It is a schematic front view of the metal detector which concerns on one embodiment of this invention. It is a block diagram which shows the structure of the test | inspection part and control part of a metal detector which concern on one embodiment of this invention. It is explanatory drawing of the differential detection principle of the metal detector which concerns on one embodiment of this invention. It is a wave form diagram which illustrates the waveform of the differential detection signal of the metal detector concerning one embodiment of the present invention. Lissajous figure (a) obtained from detection signals of foreign metal and non-defective product of metal detector according to one embodiment of the present invention, and deformation process (b) for setting detection sensitivity based on the figure data It is explanatory drawing of. It is a graph which shows the relationship between detection sensitivity instruction | indication value (alpha) specified from the foreign material sample test | inspection data of the metal detector which concerns on one embodiment of this invention, and a foreign material size. It is explanatory drawing of the display content of the display screen of the normal operation state of the metal detector which concerns on one embodiment of this invention. It is explanatory drawing of the content of the kind list display at the time of the kind change of the metal detector which concerns on one embodiment of this invention. It is explanatory drawing of the content of the screen display at the time of the sensitivity mode change of the metal detector which concerns on one embodiment of this invention. It is a block diagram which shows the structure of the metal detector of a prior art example.

Explanation of symbols

10 Metal detector 12 Conveyor (work conveying means)
14 Inspection area 16 Operation input part 17 Display (display means)
21 transmission signal generator 22 transmission coil 23 differential detector (detection means)
24 detection unit 30 control unit 31 setting unit (setting means)
32 Memory section 32d Inspection data storage area 33 Feature data creation section 34 Estimated sensitivity management section (estimated sensitivity tube means)
35 determination unit (determination means)
36 Display mode switching part (mode switching means)
37 List information generation part (List information generation means)
38 Display processing unit 50 Display screens 71 and 81 Product number (product identification information)
72, 82 Product name (type identification information)
83 Operation mode display symbols 84 and 85 Estimated detection sensitivity 86 Sensitivity mode 87 OK / NG ratio value (judgment level instruction information)
W Workpiece (inspected object)

Claims (3)

Detection means (23) for outputting a detection signal for detecting a metal in the inspection object for a plurality of kinds of inspection objects (W);
Determination means (35) for determining metal contamination by threshold determination based on the detection signal;
Setting means (31) for setting a setting parameter relating to detection by the detection means (23) for each type of the inspection object (W);
Estimating sensitivity management means the identifying the detection sensitivity represented a mixed metal the size of determinable metal foreign object by the determination means when inspecting the inspection object (W) on the basis of the setting parameters (34) When,
Wherein the identification information input in advance to identify the type of the object to be inspected (W), wherein said detection sensitivity corresponding to the type of the object to be inspected (W) (85), the information data varieties list including List information generating means (37) for generating;
Metal detector and display means (17) for displaying the variety list in a predetermined display format based on the generated information data in the list information generation means (37). The estimated sensitivity management means (34) specifies the detection sensitivity for each of a plurality of detection sensitivity modes having different setting parameters for the inspection object (W) of each product type, and based on the specified detection sensitivity Determining one of the detection sensitivity modes (86);
The list information generation means (37), a front Ki識 specific information, before and dangerous out sensitivity (85), claims and generates information data varieties list including the detection sensitivity mode (86) Item 2. The metal detector according to Item 1. Display changed according the second display mode to the first display mode and before dangerous out sensitivity (85) hide for displaying the previous danger out sensitivity (85) to the varieties of the object (W) Comprising mode switching means (36),
The list information generation means (37), to generate information data varieties list including determination level indication information (87) indicating the set threshold value in the determination means for varieties corresponding to the second display mode The metal detector according to claim 1.

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