JP5553674B2 - X-ray inspection equipment - Google Patents

Description

  The present invention relates to an X-ray inspection apparatus that detects a foreign object in an article to be inspected.

  In a production line for processed foods and the like, an X-ray inspection apparatus is used to inspect whether or not a foreign object is mixed in an inspection object such as food. This X-ray inspection apparatus, for example, irradiates an object to be inspected continuously conveyed with X-rays, detects the transmission state of the X-rays with an X-ray line sensor, and creates a two-dimensional gray image. The foreign matter in the article to be inspected is detected by the image processing means.

  Some of these X-ray inspection apparatuses have functions such as inspection for the presence or absence of missing parts in addition to the detection of foreign matter (see, for example, Patent Documents 1 and 2). In an X-ray inspection apparatus having a function of determining the presence or absence of such a missing item, data based on the amount of X-ray transmission detected by the X-ray detector is, for example, based on whether or not the data is within a predetermined range. The presence or absence of goods is determined.

JP 2007-183200 A JP 2005-106640 A

  Even for the same article to be inspected, the amount of X-ray transmission varies due to fluctuations in moisture contained in the article to be inspected due to the influence of humidity and the like. Further, in the case of a product in which candy or the like is packaged as a content, even if the product is a non-defective product, the amount of X-ray transmission varies when the density of the content varies due to temperature changes during manufacturing. However, the conventional X-ray inspection apparatus does not take into account fluctuations in X-ray transmission due to fluctuations in moisture contained in the article to be inspected or fluctuations in the density of the contents of the article to be inspected. As described above, even though the X-ray transmission amount for the same article is fluctuating, if the predetermined range for determining the presence / absence of a missing item remains fixed to a preset range, An error may occur in the determination.

  The present invention has been made to solve the above-described problems, and provides an X-ray inspection apparatus capable of improving the determination accuracy of whether there is an excess or deficiency of the contents of an inspected article such as a shortage. It is an object.

  In order to achieve the above object, an X-ray inspection apparatus according to the present invention includes an X-ray irradiator that irradiates X-rays to the articles to be inspected sequentially, and transmission of X-rays that have passed through the inspected articles. An X-ray detector for detecting an amount, a volume value calculating means for calculating a volume value of the contents of the article to be inspected based on an X-ray transmission amount detected by the X-ray detector, and the volume value calculation Excess / deficiency determination means for determining whether the inspected article is a non-defective product whose contents are not excessive or insufficient based on whether the volume value calculated by the means is within an allowable volume range; and Based on the volume value of the contents calculated by the volume value calculating means for each of a predetermined number of articles to be inspected that have been conveyed most recently from the determination results of the excess / deficiency determining means being non-defective, And an allowable range changing means for changing the allowable volume range.

  According to this configuration, the allowable volume range, which is a criterion for determining whether the contents are excessive or insufficient, is changed based on the volume values of the contents of a predetermined number of articles to be inspected that have recently been determined to be non-defective items. Since the volume value of the number is calculated based on the amount of X-ray transmission, it reflects changes in the amount of X-ray transmission due to changes in moisture contained in the inspected article and changes in the density of the contents of the inspected article. Thus, it is possible to change the allowable volume range that is a criterion for determining whether the contents are excessive or insufficient. Therefore, it is possible to improve the accuracy of determining whether the contents of the inspected item are excessive or insufficient.

  The allowable volume range is a range in which an upper limit value is determined as a value larger than a reference value by a predetermined value, and a lower limit value is determined as a value smaller than the reference value by a predetermined value. An average value of volume values of contents of the predetermined number of articles to be inspected may be calculated, and the allowable volume range may be changed by changing the reference value to the calculated average value.

  The permissible volume range is a range determined by an upper limit value and a lower limit value, and the permissible range changing means obtains a maximum value of the volume values of the contents of the predetermined number of articles to be inspected, and this maximum value. The upper limit value is changed based on the value, the minimum value of the volume values of the contents of the predetermined number of articles to be inspected is obtained, and the allowable volume range is changed by changing the lower limit value based on the minimum value. It may be configured as follows.

  The permissible range changing means includes a first operation mode for changing the permissible volume range based on the volume value calculated by the volume value calculating means for each of the predetermined number of articles to be inspected, Whether or not it is a non-defective product is measured based on whether or not the weight of the article to be inspected, which is disposed upstream of the X-ray inspection apparatus and is sequentially conveyed, is within a predetermined weight range. The weight value of the contents of the inspected article determined to be non-defective by the weight inspection apparatus for determining whether or not the weight inspection apparatus determines that the contents are non-defective in the weight inspection apparatus and the determination of the excess / deficiency determination means A second operation mode for changing the permissible volume range based on the weight value of the contents of a predetermined number of articles to be inspected that have been transported most recently from those that are non-defective. May be.

  According to this configuration, the permissible range changing unit can operate by selecting either the first operation mode or the second operation mode, and the contents of the inspected article in any of the operation modes. It is possible to improve the determination accuracy of the presence or absence of excess or deficiency.

  The present invention has the configuration described above, and has an effect that it is possible to provide an X-ray inspection apparatus capable of improving the determination accuracy of the presence / absence of the content of the inspected article.

It is the schematic which shows an example of the production line in which the X-ray inspection apparatus of the 1st Embodiment of this invention is used. 1 is a diagram showing a schematic configuration of an X-ray inspection apparatus according to a first embodiment of the present invention. It is a flowchart which shows the operation | movement in the case of inspecting the excess or deficiency of contents, such as a missing item, in the X-ray inspection apparatus of the 1st Embodiment of this invention. It is a figure which shows the relationship between the amount of X-ray permeation | transmission, and the thickness of the content of to-be-inspected goods. It is a figure which shows an example of the allowable volume range setting screen displayed on the operation indicator in the 1st Embodiment of this invention. It is a figure which shows an example of the conversion table for converting a weight value into a volume value. It is a figure which shows an example of the allowable volume range setting screen displayed on the operation indicator in the 2nd Embodiment of this invention.

  Hereinafter, preferred embodiments of the present invention will be described with reference to the drawings. In the following description, the same or corresponding elements are denoted by the same reference symbols throughout all the drawings, and redundant description thereof is omitted. Further, the present invention is not limited to the following embodiment.

(First embodiment)
FIG. 1 is a schematic view showing an example of a production line in which the X-ray inspection apparatus according to the first embodiment of the present invention is used.

  In this production line, the inspected article W is conveyed in the order of the weight inspection apparatus 1, the X-ray inspection apparatus 2, and the sorting apparatus 3. That is, the weight inspection apparatus 1 is disposed on the upstream side of the X-ray inspection apparatus 2, and the sorting apparatus 3 that distributes non-defective products and defective products is disposed on the downstream side. A conveyor (not shown) may be provided between the weight inspection apparatus 1 and the X-ray inspection apparatus 2 and between the X-ray inspection apparatus 2 and the sorting apparatus 3.

  The article W to be inspected is an article having one or more contents, for example, an article in which a predetermined number of chocolates (contents) are packaged.

  The weight inspection apparatus 1 includes a conveyor 11 that is supported by a weight sensor 12 including a load cell or the like and conveys the article W to be inspected in the direction of an arrow s. The weighing signal of the weight sensor 12 is converted into a digital signal by the A / D converter 13 and input to the control device 14. Further, a photoelectric sensor 16 for detecting the article W to be inspected is disposed on the upstream side of the conveyor 11, and a detection signal of the photoelectric sensor 16 is input to the control device 14.

  The control device 14 is configured by, for example, a microcomputer and controls the entire weight inspection device such as the conveyor 11. Further, the control device 14 determines the weight value of the inspected article W measured by the weight sensor 12 when the inspected article W is transferred to a predetermined position on the conveyor 11 based on the detection signal of the photoelectric sensor 16. When the weight value of the inspected article W acquired and weighed by the weight sensor 12 is within a predetermined weight range set in advance, it is determined as “non-defective”, and when it is outside the predetermined weight range, “defective product” is determined. judge. Then, this determination signal N1 is transmitted to the control device 33 of the distribution device 3.

  The operation indicator 15 is configured by using, for example, a touch panel display and the like, and includes input means for operating the weight inspection apparatus and setting operation condition information thereof, and the input means, the weight value of the article, total data, and the like. Display means for displaying on a screen (display screen).

  In addition, the control device 14 inputs a signal from the operation indicator 15 and outputs a signal such as data to be displayed on the operation indicator 15. The operation indicator 15 is used to set operation condition information of the weight inspection device such as the conveyor operation speed, and the set operation condition information is stored in a storage unit in the control device 14.

  FIG. 2 is a diagram showing a schematic configuration of the X-ray inspection apparatus 2. In FIG. 1, the conveyor 21 is simply illustrated with two rollers and a belt, but the conveyor 21 in the present embodiment includes three rollers and a belt as illustrated in FIG. 2.

  This X-ray inspection apparatus 2 is an X-ray inspection apparatus that determines whether or not the article to be inspected W is a non-defective product for each of a plurality of inspection items including a foreign object inspection and a content excess / deficiency inspection.

  The X-ray inspection apparatus 2 includes a conveyor 21 that conveys an article W to be inspected in a horizontal direction indicated by an arrow s, a X-ray irradiator 22 that irradiates X-rays, and an X-ray within a casing 26 that shields X-rays. For example, an X-ray detector 23 composed of an X-ray line sensor and a control device 24 are provided. Furthermore, an operation indicator 25 for displaying a transmitted X-ray image or the like on the screen and operating the X-ray inspection apparatus 2 is provided on the front side of the housing 26. The conveyor 21, the X-ray irradiator 22, the X-ray detector 23, and the operation indicator 25 are controlled by the control device 24. In addition, a photoelectric sensor 29 for detecting the article W to be inspected is disposed on the upstream side of the conveyor 21, and a detection signal of the photoelectric sensor 29 is input to the control device 24. The photoelectric sensor 29 is provided for the control device 24 to detect the timing at which the article W to be inspected passes through the X-ray irradiation range, and is composed of a pair of light projectors and light receivers arranged horizontally across the conveyor 21. ing.

  The casing 26 is formed with, for example, a rectangular opening that serves as an inlet and an outlet for the article W to be inspected. The conveyor 21 conveys the article W to be inspected in the horizontal direction from the entrance to the exit of the housing 26, and the carry-in end portion and the carry-out end portion are disposed so as to protrude from the housing 26. Goods 27 on the inlet side and goodwill 28 on the outlet side are provided to prevent X-rays from leaking in the direction of the inlet and outlet.

  The X-ray irradiator 22 is disposed in the upper part of the housing 26 and irradiates X-rays downward through a slit. X-rays through the slits are irradiated in a fan shape, and are irradiated on the conveyor 21 in a line shape having a predetermined width and length.

  The X-ray detector 23 is disposed between the belts of the conveyor 21 and immediately below the conveyance surface, and detects X-rays transmitted through the belt to be the conveyance surface of the article W to be inspected and the conveyor 21. In the X-ray detector 23, a large number of X-ray detection elements are horizontally arranged on the straight line in a direction orthogonal to the conveying direction of the article to be inspected by the conveyor 21 at a constant pitch. Each X-ray detection element detects the amount of X-ray transmission. As is well known, the X-ray detection element is composed of a scintillator and a photodiode. All the X-ray detection elements provided in the X-ray detector 23 are regarded as one line, and the amount of X-ray transmission detected by each X-ray detection element constituting this one line is transmitted from the X-ray detector 23 to the X-ray transmission. It is sequentially output as a quantity signal. As the article W to be inspected is conveyed, sequential output from the aforementioned one line is repeated. This one-line output repetition rate (the number of repetitions per unit time) is hereinafter referred to as scan speed.

  The X-ray transmission amount signal sequentially output from the X-ray detector 23 is converted into a digital signal via an A / D converter (not shown) and input to the control device 24.

  The control device 24 is constituted by, for example, a microcomputer, and includes a CPU and a storage unit including a nonvolatile memory in which a RAM and an execution program of the CPU are stored, and performs overall operation control of the X-ray inspection apparatus. Do. Further, all information to be stored during operation is stored in the storage unit. The control device 24 creates a two-dimensional X-ray image from sequentially input X-ray transmission amount signals, determines whether the predetermined inspection item is a non-defective product or a defective product, and the overall determination result ( A determination signal N2 indicating the result of step S6 in FIG. 3 is transmitted to the control device 33 of the distribution device 3. The control device 24 also functions as a volume value calculating unit, an excess / deficiency determining unit, an allowable range changing unit, and the like.

  The operation indicator 25 is configured using, for example, a touch panel display and the like. An input unit for operating the X-ray inspection apparatus and setting operating condition information thereof, and an X-ray image and a determination result are displayed on a screen (display screen). Display means for displaying in ().

  Further, the control device 24 inputs a signal from the operation indicator 25 and outputs a signal such as data to be displayed on the operation indicator 25. In addition, operation condition information of the X-ray inspection apparatus such as the conveyor operation speed is set using the operation indicator 25, and the set operation condition information is stored in a storage unit in the control device 24.

  The distribution apparatus 3 shown in FIG. 1 includes, for example, a conveyor 31, a distribution arm 32 disposed on the side of the conveyor 31 in order to distribute articles on the conveyor 31, a conveyor 31, and a distribution arm 32. And a control device 33 for controlling.

  The control device 33 is determined as a defective product based on, for example, the determination signal N1 from the control device 14 of the weight inspection device 1 and the determination signal N2 from the control device 24 of the X-ray inspection device 2. The article W to be inspected is removed from the conveyor 31 by horizontally rotating the sorting arm 32, and only the article to be inspected W determined to be a non-defective product by either the weight inspection apparatus 1 or the X-ray inspection apparatus 2 is the conveyor. After passing 31, it is conveyed to a downstream device (not shown), for example, a boxing device.

  Next, an operation in the case where the X-ray inspection apparatus 2 of the present embodiment performs an inspection for excess or deficiency of contents such as a shortage will be described. A flowchart showing this operation is shown in FIG. This operation is realized by the control device 24.

  First, the outline will be described. The control device 24 generates a two-dimensional X-ray image based on the X-ray transmission amount obtained from the X-ray detector 23. Next, the region of the X-ray image is divided into a background region and a region other than the background (that is, the content region) by binarization processing. Next, the thickness of the content is calculated based on the X-ray transmission amount for each pixel in the content area, and the volume value of the content is calculated based on the thickness calculated for each pixel. Next, based on the volume value of the contents, it is determined whether the inspected article W is a non-defective product or a defective product (a missing product or an overdose product).

  First, in step S1, an X-ray transmission amount signal for one line detected by the X-ray detector 23 is acquired at predetermined time intervals, and the article W to be inspected and its background portion based on those X-ray transmission amount signals. A two-dimensional X-ray image including At this time, the timing at which the article to be inspected W passes through the fan-shaped X-ray irradiation range is determined by a signal from the photoelectric sensor 29. In other words, in step S1, data related to the amount of X-ray transmission for one line is acquired from the X-ray detector 23 at predetermined time intervals, and the data at each time is connected in the order of passage of time, thereby A two-dimensional X-ray image (X-ray image data) including the background portion is created.

  Next, in step S2, the region of the X-ray image generated in step S1 is divided into a background region and a content region other than the background by binarization processing. In the binarization processing, for each pixel constituting the X-ray image, the X-ray transmission amount value corresponding to the pixel is compared with a predetermined threshold value, and the background region and the content region are determined by the magnitude relationship between these values. And extract. The threshold value used in this binarization process is appropriately determined in advance according to the article to be inspected W, which is a specimen, by performing a test or the like in advance.

  And the volume value of the content of the to-be-inspected article W is calculated by following step S3, S4. First, in step S3, each pixel Pi corresponding to the content area on the X-ray image (i = 1, 2,..., N, n is the number of pixels constituting the content on the X-ray image). , The thickness Di of the content corresponding to each pixel Pi is calculated based on the X-ray transmission amount corresponding to each pixel Pi (that is, the X-ray transmission amount detected by each X-ray detection element). This thickness Di is calculated based on a table or a mathematical expression showing the relationship between the amount of X-ray transmission and the thickness of the contents of the article W to be inspected. This table or mathematical expression satisfies the relationship as shown in FIG. 4, and is created and stored in advance by performing a test or the like. FIG. 4 is a diagram showing the relationship between the X-ray transmission amount and the thickness of the contents of the article W to be inspected, and Xo is the X-ray transmission amount when there is no article W to be inspected on the conveyor 21.

  Subsequently, in step S4, the thicknesses D1, D2,..., Dn calculated for all the pixels P1, P2,. Then, the volume value of the contents is calculated by multiplying the total value by the area of one pixel. The area of one pixel is, for example, a value a obtained by multiplying the conveyance speed of the conveyor 21 by the scan speed described above and the arrangement pitch of the X-ray detection elements. In addition, since X-rays are irradiated in a fan shape, when the distance between the X-ray detector 23 and the transport surface of the conveyor 21 is long, a value obtained by multiplying the value a by a preset ratio less than 1 is 1 The area of the pixel may be used.

  Next, in step S5, based on the volume value of the contents calculated in step S4, it is determined whether the inspected article W is a good product or a defective product. Specifically, if the volume value of the content is within the allowable volume range, it is determined that the content is a non-defective product, and if the content is outside the allowable volume range, the content is defective. Is determined. Here, when the volume value of the content is outside the allowable volume range, if it is smaller than the lower limit value of the allowable volume range, it is determined that the product is missing due to missing contents, etc. Alternatively, it may be determined that the content is an excessive quantity due to the number of contents being greater than a predetermined number.

  Next, in step S6, based on the determination result in step S5 and the determination result in other inspection items such as foreign matter inspection, it is comprehensively determined whether or not the inspected article W is a non-defective product. Only when it is determined that all the inspection items are non-defective (that is, the comprehensive determination is non-defective), the process proceeds to step S7, and the allowable volume range is updated.

  The processes in steps S1 to S7 are performed every time the article W to be inspected is conveyed. Although not shown, the control device 24 determines whether or not a foreign object is included in the article W to be inspected based on the X-ray image created in step S1 when performing the foreign object inspection. If not, the inspected article W is determined as a non-defective product, and if included, it is determined as a defective product. This foreign matter inspection is performed by a known method.

  In the present embodiment, the allowable volume range used for the pass / fail determination in step S5 is first set and updated (changed) in step S7. This will be described below.

  FIG. 5 is a diagram illustrating an example of the allowable volume range setting screen 41 displayed on the operation display 25. The allowable volume range setting screen 41 is called from a predetermined display screen (not shown), and when the return key 49 is touched, the display returns to the called display screen. In the allowable volume range setting screen 41, a reference value setting key 42, an upper limit determined value setting key 43, a lower limit determined value setting key 44, and an overcorrection limit value setting key 46 are displayed. When these touch keys are touched, a numeric keypad (not shown) is displayed. Each value is displayed by touching the numeric keypad. This set value is displayed on each touch key.

  Here, the allowable volume range is a range in which (reference value + upper limit determination value) is an upper limit value and (reference value−lower limit determination value) is a lower limit value. When the reference value is corrected (changed) as described later, the allowable volume range has (correction reference value + upper limit determination value) as the upper limit value and (correction reference value−lower limit determination value) as the lower limit value. It is changed to the range.

  Each time the self-reference value correction key 47 and the reference value correction key 48 based on the weight signal are touched, the display is switched between “ON” and “OFF”. However, when the self-reference value correction key 47 and the reference value correction key 48 based on the weight signal are not simultaneously “ON”, when one is “ON” and the other is “OFF”, the other is touched to “ When set to “ON”, one side is switched to “OFF”.

  When either the self-reference value correction key 47 or the reference value correction key 48 based on the weight signal is “ON”, the reference value is automatically corrected during operation of the X-ray inspection apparatus 2. The corrected current reference value is displayed in the display area 45 as a corrected reference value. The overcorrection limit value is a value indicating the limit of the range in which the reference value is automatically corrected during operation. As shown in FIG. 5, when the set reference value is 22340 and the overcorrection limit value is 100, it is automatically corrected within the range of 22340 plus or minus 100 (within the range of 22240 to 22440). Is possible.

The unit of the numerical values (reference value, upper limit determination value, lower limit determination value, correction reference value, and overcorrection limit value) displayed on the allowable volume range setting screen 41 is [mm ³ ].

  Next, the method for updating the allowable volume range in step S7 will be described first when the self-reference value correction key 47 is turned on (when the allowable range changing means is in the first operation mode). In this case, the control device 24 does not need to acquire the weight value D1 (FIG. 1) from the control device 14 of the weight inspection device 1.

  The control device 24 stores the volume value of the contents of the article W to be inspected calculated in step S4 for the non-defective items whose determination results for all the inspection items are in step S6. Then, an average value of predetermined m (m is a plurality), for example, 10 volume values stored most recently, is calculated, and the average value is set as a correction reference value. In this way, by modifying (changing) the reference value, the allowable volume range is also changed as described above. Note that when the corresponding volume value is less than the above m at the start of operation, the allowable volume range need not be updated.

  Next, a method for updating the allowable volume range when the operation is performed with the reference value correction key 48 based on the weight signal set to “ON” (when the allowable range changing means is in the second operation mode) will be described. While the reference value correction key 48 based on the weight signal is in the “ON” state, the control device 24 continues to transmit the weight value request signal to the control device 14 of the weight inspection device 1. While receiving the weight value request signal, the control device 14 of the weight inspection apparatus 1 determines a package (a packaging bag or a package other than the contents) from the total weight of the article W to be inspected that is determined to be non-defective. The weight value of the contents is calculated by subtracting the weight of the packaging container such as a box, and the weight value D1 is transmitted to the control device 24. The control device 24 stores the transmitted weight value D1.

  And the control apparatus 24 is memorize | stored about the to-be-inspected goods W which were the to-be-inspected goods W whose determination result of all the inspection items in step S6 is non-defective, and was conveyed to the X-ray inspection apparatus 2 most recently. An average weight value of predetermined m pieces of weight values is calculated, the average weight value is converted into a volume value, and the converted volume value is set as a correction reference value. By correcting the reference value in this way, the allowable volume range is also changed. Here, in order to convert the average weight value into the volume value, the control device 24 stores, for example, a conversion table T1 for converting the weight value into the volume value as shown in FIG. Based on T1, the average weight value is converted into a volume value. When the average weight value is a weight value that is not stored in the conversion table T1, the volume value is calculated by interpolation (for example, linear interpolation). When the corresponding weight value is less than the above m at the start of operation, the allowable volume range need not be updated.

  As described above, when the weight inspection apparatus 1 is arranged on the upstream side of the X-ray inspection apparatus 2, the correction reference value is calculated from the weight value of the article W to be inspected obtained by the weight inspection apparatus 1 and allowed. The volume range may be updated.

  Here, the control device 24 stores the weight value D1 of the contents of the article W to be inspected acquired from the weight inspection device 1. However, the control device 24 converts the volume value into the volume value in advance and stores it in step S6. The average value of the m volume values stored for the article W to be inspected, which is a non-defective article W for which the determination results of all the inspection items are non-defective, and has been transported most recently to the X-ray inspection apparatus 2 The average value may be calculated as the correction reference value.

  In the present embodiment, when the self-reference value correction key 47 is turned on and the operation is performed, the allowable volume range that becomes the determination criterion in the inspection of the excess or deficiency of the contents is the predetermined m number of items that have been determined to be non-defective products. Since the volume values of the m pieces are changed based on the amount of X-ray transmission, the change in the moisture contained in the article to be inspected or the state of the article to be inspected is changed based on the volume value of the contents of the article to be inspected. Reflecting the variation in the amount of X-ray transmission due to the variation in the density of the contents, the allowable volume range serving as a criterion for determining whether the contents are excessive or insufficient can be changed. Therefore, it is possible to improve the accuracy of determining whether the contents of the inspected item are excessive or insufficient.

  When the amount of X-ray transmission decreases (increases) due to an increase (decrease) in moisture contained in the inspected article and an increase (decrease) in the density of the contents of the inspected article, the calculation is based on the amount of X-ray transmission. The thickness increases (decreases) (see FIG. 4), and the volume value also increases (decreases). On the other hand, the weight value increases (decreases) due to the increase (decrease) in moisture and the increase (decrease) in density. That is, the weight value increases (decreases) in the same manner as the volume value increases (decreases) due to the increase (decrease) in moisture and the increase (decrease) in density. Even when the operation is performed, the allowable volume range is changed based on the weight value, so that the determination accuracy of whether the contents of the inspected article are excessive or insufficient can be improved.

(Second Embodiment)
The configuration in the second embodiment is the same as the configuration shown in FIGS. 1 and 2 of the first embodiment, and a description thereof will be omitted. In the second embodiment, the method for setting and changing the allowable volume range is different from that in the first embodiment.

  FIG. 7 is a diagram illustrating an example of the allowable volume range setting screen 51 displayed on the operation display 25 in the second embodiment. This allowable volume range setting screen 51 is called from a predetermined display screen (not shown), and when the return key 60 is touched, the display returns to the called display screen. In the allowable volume range setting screen 51, an upper limit value setting key 52, a lower limit value setting key 53, an upper limit value overcorrection limit value setting key 55, and a lower limit value overcorrection limit value setting key 57 are displayed, and touching these touch keys. A numeric keypad (not shown) is displayed, and each value can be set by touching the numeric keypad. This set value is displayed on each touch key.

  Here, the allowable volume range is a range not less than the lower limit and not more than the upper limit. When the lower limit value and the upper limit value are modified (changed) as described later, the allowable volume range is changed to a range that is greater than or equal to the modified lower limit value and less than or equal to the modified upper limit value.

  Each time the self upper / lower limit correction key 58 and the weight signal upper / lower limit correction key 59 are touched, the display is switched between “ON” and “OFF”. However, the self upper / lower limit correction key 58 and the weight signal upper / lower limit correction key 59 are not simultaneously “ON”. When one is “ON” and the other is “OFF”, the other is touched. When “ON” is selected, one of the two switches to “OFF”.

  When either the self upper / lower limit correction key 58 or the upper / lower limit correction key 59 based on the weight signal is “ON”, the upper limit value and the lower limit value are automatically corrected during operation of the X-ray inspection apparatus 2. Is done. The corrected current upper limit value is displayed in the display area 54 as the corrected upper limit value, and the corrected current lower limit value is displayed in the display area 56 as the corrected lower limit value. The upper limit overcorrection limit value indicates the limit of the range in which the upper limit value is automatically corrected during operation. The lower limit overcorrection limit value is the limit of the range in which the lower limit value is automatically corrected during operation. Is a value indicating As shown in FIG. 7, when the set upper limit value is 22600 and the upper limit overcorrection limit value is 100, the upper limit value is automatically set within the range of 22600 plus or minus 100 (within the range of 22500 to 22700). Can be modified. Similarly, when the set lower limit value is 22250 and the lower limit value overcorrection limit value is 100, the lower limit value is automatically corrected within the range of 22250 plus or minus 100 (within the range of 22150 to 22350). Is possible.

The unit of the numerical values (upper limit, lower limit, correction upper limit, correction lower limit, upper limit overcorrection limit and lower limit overcorrection limit) displayed on the allowable volume range setting screen 51 is [mm ³ ].

  Next, with regard to the method for updating the allowable volume range in step S7 (FIG. 3), first, when the self-upper / lower limit correction key 58 is turned on (when the allowable range changing means is in the first operation mode). Will be described. In this case, the control device 24 does not need to acquire the weight value D1 (FIG. 1) from the control device 14 of the weight inspection device 1.

  The control device 24 stores the volume value of the contents of the article W to be inspected calculated in step S4 for the non-defective items whose determination results for all the inspection items are in step S6. Then, a maximum value and a minimum value are selected from predetermined k pieces (k is a plurality), for example, 10 volume values stored most recently, and (maximum value + b) is set as a correction upper limit value. Let b) be the lower limit of correction (b is a predetermined value). Thus, the allowable volume range is changed as described above by correcting the upper limit value and the lower limit value. Note that when the corresponding volume value is less than the above k at the start of operation, the allowable volume range need not be updated.

  Next, a method for updating the allowable volume range when the operation is performed with the upper / lower limit correction key 59 based on the weight signal set to “ON” (when the allowable range changing means is in the second operation mode) will be described. While the upper / lower limit correction key 59 based on the weight signal is in the “ON” state, the control device 24 continues to transmit the weight value request signal to the control device 14 of the weight inspection device 1. While receiving the weight value request signal, the control device 14 of the weight inspection apparatus 1 calculates the weight value of the contents of the inspected article W determined to be non-defective as described above, and controls the weight value D1. Transmit to device 24. The control device 24 stores the transmitted weight value D1.

  And the control apparatus 24 is memorize | stored about the to-be-inspected goods W which were the to-be-inspected goods W whose determination result of all the inspection items in step S6 is non-defective, and was conveyed to the X-ray inspection apparatus 2 most recently. The maximum weight value and the minimum weight value are selected from the predetermined k weight values. Then, the selected maximum weight value is converted into a volume value (this volume value is set as x), (x + b) is set as a correction upper limit value, and the minimum weight value is converted into a volume value (this volume value is set as y). Then, (y−b) is set to the correction lower limit value (b is a predetermined value). Thus, the allowable volume range is changed as described above by correcting the upper limit value and the lower limit value. The method of converting the maximum weight value and the minimum weight value into the volume value is the same as the case of converting the average weight value into the volume value in the first embodiment, and is performed based on, for example, the conversion table T1 shown in FIG. When the corresponding weight value is less than the k pieces at the start of operation, the allowable volume range need not be updated.

  As described above, when the weight inspection apparatus 1 is arranged on the upstream side of the X-ray inspection apparatus 2, the correction upper limit value that determines the allowable volume range from the weight value of the article W to be inspected obtained by the weight inspection apparatus 1. And the correction lower limit value may be calculated, and the allowable volume range may be updated.

  Here, the control device 24 stores the weight value D1 of the contents of the article W to be inspected acquired from the weight inspection device 1. However, the control device 24 converts the volume value into the volume value in advance and stores it in step S6. The inspection result W of all the inspection items is a non-defective product, and the maximum value among the k volume values stored for the inspection product W that has been transported most recently to the X-ray inspection apparatus 2 A value and a minimum value may be selected to be a correction upper limit value and a correction lower limit value.

  In the present embodiment, when the operation is performed with the self upper / lower limit correction key 58 set to “ON”, as in the case where the operation is performed with the self reference value correction key 47 set to “ON” in the first embodiment, The allowable volume range, which is a criterion for determining whether the contents are excessive or insufficient, can be changed to reflect fluctuations in the amount of X-ray transmission due to fluctuations in moisture contained in the contents and fluctuations in the density of the contents of the article to be inspected. Therefore, it is possible to improve the accuracy of determining whether the contents of the inspected item are excessive or insufficient.

  Further, when the operation is performed with the upper / lower limit correction key 59 based on the weight signal set to “ON”, the weight value is changed to the same as when the reference value correction key 48 based on the weight signal is set to “ON” in the first embodiment. By changing the allowable volume range based on this, it is possible to improve the determination accuracy of whether the contents of the inspected article are excessive or insufficient.

  INDUSTRIAL APPLICABILITY The present invention is useful as an X-ray inspection apparatus or the like that can improve the determination accuracy of an inspection for missing items.

DESCRIPTION OF SYMBOLS 1 Weight inspection apparatus 2 X-ray inspection apparatus 3 Sorting apparatus 21 Conveyor 22 X-ray irradiator 23 X-ray detector 24 Control apparatus 25 Operation indicator

Claims (4)

An X-ray irradiator that irradiates X-rays to the inspected articles conveyed in sequence;
An X-ray detector for detecting the amount of X-ray transmitted through the article to be inspected;
Volume value calculating means for calculating the volume value of the contents of the inspected article based on the amount of X-ray transmission detected by the X-ray detector;
Excess / deficiency determination for determining whether the inspected article is a non-defective product whose contents are not excessive or insufficient based on whether or not the volume value calculated by the volume value calculating means is within an allowable volume range. Means,
Based on the volume value of the contents calculated by the volume value calculating means for each of a predetermined number of articles to be inspected that have been transported most recently from the determination results of the excess / deficiency determining means being non-defective products, An allowable range changing means for changing the allowable volume range,
The allowable volume range is a range in which an upper limit value is determined as a value larger than a reference value by a predetermined value, and a lower limit value is determined as a value smaller than the reference value by a predetermined value,
The allowable range changing means calculates an average value of volume values of the contents of the predetermined number of inspected articles, and changes the allowable volume range by changing the reference value to the calculated average value. Configured X- ray inspection device. An X-ray irradiator that irradiates X-rays to the inspected articles conveyed in sequence;
An X-ray detector for detecting the amount of X-ray transmitted through the article to be inspected;
Volume value calculating means for calculating the volume value of the contents of the inspected article based on the amount of X-ray transmission detected by the X-ray detector;
Excess / deficiency determination for determining whether the inspected article is a non-defective product whose contents are not excessive or insufficient based on whether or not the volume value calculated by the volume value calculating means is within an allowable volume range. Means,
Based on the volume value of the contents calculated by the volume value calculating means for each of a predetermined number of articles to be inspected that have been transported most recently from the determination results of the excess / deficiency determining means being non-defective products, An allowable range changing means for changing the allowable volume range,
The allowable volume range is a range determined by an upper limit value and a lower limit value,
The allowable range changing means obtains the maximum value of the volume value of the contents of the predetermined number of articles to be inspected, changes the upper limit based on the maximum value, and sets the contents of the contents of the predetermined number of articles to be inspected. An X- ray inspection apparatus configured to change the allowable volume range by obtaining a minimum value of a volume value and changing the lower limit value based on the minimum value. An X-ray irradiator that irradiates X-rays to the inspected articles conveyed in sequence;
An X-ray detector for detecting the amount of X-ray transmitted through the article to be inspected;
Volume value calculating means for calculating the volume value of the contents of the inspected article based on the amount of X-ray transmission detected by the X-ray detector;
Excess / deficiency determination for determining whether the inspected article is a non-defective product whose contents are not excessive or insufficient based on whether or not the volume value calculated by the volume value calculating means is within an allowable volume range. Means,
Based on the volume value of the contents calculated by the volume value calculating means for each of a predetermined number of articles to be inspected that have been transported most recently from the determination results of the excess / deficiency determining means being non-defective products, An allowable range changing means for changing the allowable volume range,
The allowable range changing means includes
A first operation mode for changing the allowable volume range based on the volume value calculated by the volume value calculating means for each of the predetermined number of inspected articles;
Whether the product is in good quality based on whether or not the weight of the inspected article disposed on the upstream side of the X-ray inspection apparatus and sequentially conveyed is measured and the measured weight is within a predetermined weight range. The weight value of the contents of the inspected article determined to be non-defective by the weight inspection apparatus for determining whether or not is obtained from the weight inspection apparatus, is determined to be non-defective in the weight inspection apparatus, and A second operation mode for changing the permissible volume range based on the weight value of the contents of a predetermined number of articles to be inspected that have been transported most recently from those that are non-defective. X- ray inspection equipment. The allowable range changing means includes
A first operation mode for changing the allowable volume range based on the volume value calculated by the volume value calculating means for each of the predetermined number of inspected articles;
Whether the product is in good quality based on whether or not the weight of the inspected article disposed on the upstream side of the X-ray inspection apparatus and sequentially conveyed is measured and the measured weight is within a predetermined weight range. The weight value of the contents of the inspected article determined to be non-defective by the weight inspection apparatus for determining whether or not is obtained from the weight inspection apparatus, is determined to be non-defective in the weight inspection apparatus, and A second operation mode for changing the permissible volume range based on the weight value of the contents of a predetermined number of articles to be inspected that have been transported most recently from those that are non-defective. The X-ray inspection apparatus according to claim 1 or 2.

Images