Inspection system and inspection method

Abstract

To provide an inspection system and a method for inspection that can precisely determine an abnormality of local unevenness of a bead method foam molding body.SOLUTION: A measurement unit measures the unevenness of the surface of a specific inspection region of a bead method foam molding body. The determination unit determines whether the unevenness is beyond an acceptable range. The inspection region includes a region in contact with a filling port for supplying a raw material in the pattern for molding the bead method foam molding body. In an embodiment, the inspection system and the method for inspection can be used in any manner.SELECTED DRAWING: Figure 1

Description

[Technical Field]

[0001] The present invention relates to an inspection system and an inspection method, and more particularly to an inspection system and an inspection method for determining the quality of foam molded articles produced by the bead method. [Background technology]

[0002] Foam-molded products, including bead-process foam molded products (sometimes referred to herein as "in-mold bead foamed products"), are produced by foam molding in a foam molding machine. The bead process is a technique in which foamed resin particles (sometimes referred to herein as "foam beads") formed by foaming a raw material are injected (sometimes referred to herein as "filling") into a molding mold and heated to weld (sometimes referred to herein as "fusing") the beads to each other, thereby forming them into a shape that conforms to the inner surface of the mold. The produced foam-molded products are typically inspected for quality and judged as pass or fail. Defective products that do not pass the inspection are rejected, and non-defective products that pass the inspection are shipped. Various methods have been proposed to improve the efficiency of the inspection process.

[0003] For example, Patent Document 1 discloses a method for rejecting defective products in which foam-molded products removed from a foam molding machine are transferred to a transfer line for transporting to the next process, the weight of the foam-molded products being transferred sequentially along the line is measured, the measured value is compared with a predetermined weight value, and if the measured value does not meet the predetermined weight value, the foam-molded product is rejected from the transfer line.The method proposes a method in which products weighing less than a certain weight are rejected as defective products and products with a certain weight are supplied as non-defective products. [Prior art documents] [Patent documents]

[0004] [Patent Document 1] Japanese Patent Application Publication No. 6-7747 Summary of the Invention [Problem to be solved by the invention]

[0005] However, although the method described in Patent Document 1 is effective for inspecting the weight of foam-molded products, it cannot be applied to other inspections, such as inspections for local irregularities or the presence or absence of foreign matter. Weight abnormalities are often caused by insufficient filling of the foam beads into the mold, while local irregularities can be caused by, for example, overfilling of the foam beads into the mold or removal from the mold (sometimes referred to as "demolding" in this application), and the causes of these abnormalities are also different. In other words, the quality required by consumers for foam-molded products varies widely, and even if weight inspection can be realized, it is not necessarily applicable to other inspections.

[0006] The present invention has been made in consideration of the above points, and one of the objects of the present invention is to provide an inspection system and an inspection method that can accurately determine abnormalities in localized unevenness of bead method foam molded bodies. [Means for solving the problem]

[0007] (1) The present invention has been made to solve the above-mentioned problems, and one aspect of the present invention is an inspection system including at least a measurement unit that measures the unevenness of the surface in a predetermined inspection area of ​​a bead method foam molded body, and a judgment unit that judges whether the unevenness exceeds a predetermined tolerance range.

[0008] (2) Another aspect of the present invention is an inspection system in which the inspection area includes an area that was in contact with a filling port through which raw material is supplied to a mold for forming the bead method foam molded article.

[0009] (3) Another aspect of the present invention is an inspection system in which the inspection area includes an area that was in contact with a mold release tool that releases the foam molded article by the bead method from the mold.

[0010] (4) Another aspect of the present invention is an inspection system in which the inspection area includes both an area that was in contact with a filling port that supplies raw material to a mold for molding the bead method foam molded body, and an area that was in contact with a mold release tool that releases the bead method foam molded body from the mold. [Effects of the Invention]

[0011] According to the present invention, abnormalities in local unevenness can be accurately determined. [Brief explanation of the drawings]

[0012] [Figure 1] 1 is an external view showing an example of the configuration of an inspection system 1 according to the present embodiment. [Figure 2] FIG. 2 is a schematic block diagram showing an example of the functional configuration of an inspection control unit according to the present embodiment. [Figure 3] FIG. 1 is a cross-sectional view showing an example of the configuration of a molding machine used to mold in-mold bead foam products. [Figure 4] FIG. 1 is a bottom view showing an example of irregularities that may occur during molding of an in-mold bead foam product. [Figure 5] FIG. 1 is a perspective view showing an example of irregularities that may occur during molding of an in-mold bead foam product. [Figure 6] FIG. 10 is an explanatory diagram showing an example of a dented abnormality in an in-mold bead foam product. [Figure 7] FIG. 1 is an explanatory diagram showing an example of a convex abnormality in an in-mold bead foam product. [Figure 8] FIG. 10 is an explanatory diagram showing an example of setting a start time and a measurement time. [Figure 9] FIG. 3 is a diagram showing a first example of a setting screen according to the embodiment. [Figure 10] FIG. 10 is a diagram showing a second example of a setting screen according to the embodiment. [Figure 11] FIG. 10 is a diagram showing a third example of a setting screen according to the embodiment. DETAILED DESCRIPTION OF THE INVENTION

[0013] Hereinafter, an embodiment of the present invention will be described with reference to the drawings. First, an overview of this embodiment will be described. FIG. 1 is an external view showing an example of the configuration of an inspection system 1 according to this embodiment. The inspection system 1 measures the unevenness of predetermined inspection areas present on a predetermined surface of an in-mold bead foam product for an inspection object Sm, and determines whether the unevenness exceeds a predetermined tolerance. In the example shown, five inspection areas exist on the same surface for one in-mold bead foam product. The number and positions of the inspection areas may vary depending on the inspection object. The number of inspection areas is a predetermined number of one or more. The inspection areas include either an area that was in contact with the filling port of a filling machine that supplies raw material to a mold used to form the in-mold bead foam product (sometimes referred to herein as a "filling port mark") or an area that was in contact with a mold release tool that releases the in-mold bead foam product from the mold (sometimes referred to herein as a "pin mark"). The filler and release tool of the present application are often placed on the same surface of the in-mold bead foam product. For example, in the case of an in-mold bead foam product formed as a box, they are often placed on the backside of the outer bottom of the box. The filler and release tool may also be placed on the inner bottom of the box. In the present application, the object of inspection is unevenness that occurs on the surface observed from a direction intersecting the conveying surface (for example, the Z direction, either positive or negative).

[0014] Next, an example configuration of the inspection system 1 will be described with reference to FIG. 1. The inspection system 1 includes an inspection control unit 10, an item detection unit 22, a measurement unit 24, an image capture unit 26 (if necessary), a discharge detection unit 28, a sensor support unit 32, an item removal unit 40, a control panel 45, a transport unit 50, and a stopper 56. In this application, the transport direction and vertical direction of the inspection target Sm are sometimes referred to as the "x direction" and "z direction," respectively. The x direction is sometimes referred to as the "forward" direction, and the forwardmost portion is sometimes referred to as the "front end" or "front end." The opposite direction of the x direction is sometimes referred to as the "reverse x direction" or "rear," and the rearmost portion is sometimes referred to as the "rear end" or "end." The opposite direction of the z direction is sometimes referred to as the "reverse z direction" or "vertical direction." The direction perpendicular to the transport direction and the vertical direction, and corresponding to the left of the transport direction, is sometimes referred to as the "y direction" or "left." The direction corresponding to the right of the conveying direction in relation to the conveying direction is sometimes called the "reverse y direction" or "rightward." In Figure 1, the x, y, and z directions are represented as the right, depth, and upward, respectively. In addition, the main surface of the inspection object Sm facing the z direction is sometimes called the "front surface," and the main surface facing the vertical direction (the opposite direction of the z direction) is sometimes called the "back surface." The part of the back surface that is almost flat and has no irregularities is sometimes called the "reference surface."

[0015] The inspection control unit 10 controls the operation of the inspection system 1. Specifically, the inspection control unit 10 accepts user operations and can set parameters in accordance with the accepted operations. The inspection control unit 10 determines whether the inspection object Sm has been detected based on an item detection signal (described below) input from the item detection unit 22. The inspection control unit 10 acquires measurement data from the measurement unit 24 at a timing based on the set parameters. The set parameters include a measurement start time and a measurement time (described below). The inspection control unit 10 determines whether or not there is an abnormality in the unevenness of the back surface of the inspection object Sm based on whether or not the unevenness indicated in the measurement data exceeds a predetermined allowable range of unevenness based on the set parameters. The set parameters also include an allowable range of unevenness (described below). The unevenness corresponds to the surface height, as described below. In the illustrated example, the surface height is obtained by measuring the distance from the measurement unit 24 to the inspection object Sm. Based on the determination result, the inspection control unit 10 controls whether or not to reject the inspection object Sm.

[0016] The inspection system 1 may be combined with an inspection means that performs inspection from another perspective, for example, a system that determines whether or not there are abnormalities in the surface condition. In this case, it is particularly effective to combine it with a system that inspects the inner surface of the inspection object Sm, for example, the inner surface or bottom surface of the box in the case of a box-shaped in-mold bead molded product, or with a system that inspects printing defects or abnormal sticker application in the case of processing such as printing or sticker application on the side. The system for determining abnormalities in appearance can use a known image inspection system that compares and collates an inspection image with a master image such as the one shown below.

[0017] The inspection control unit 10 determines whether or not there is an abnormality in the surface condition of the inspection object Sm shown in the image data input from the photographing unit 26. The inspection control unit 10 can, for example, compare a pre-registered master image with the image of the inspection object Sm and determine whether or not there is an abnormality based on whether or not the similarity between the two images is lower than a predetermined limit value of similarity. A master image to be used for this comparison is registered in the inspection control unit 10 as one of the parameters. An existing image of a normal product photographed in advance can be used as the master image. When the inspection control unit 10 determines that either or both of the irregularities based on the height and the abnormality of the surface condition based on the image are present, it outputs a removal command to the item removal unit 40 to instruct the item removal unit 40 to remove the object to be inspected. The inspection control unit 10 may be, for example, a dedicated terminal device, or may be a general-purpose information processing device such as a personal computer, a tablet terminal device, etc. An example of the functional configuration of the inspection control unit 10 will be described later.

[0018] The item detection unit 22 detects items to be inspected Sm transported to the transport unit 50. Any method may be adopted for the item detection unit 22 as long as it can detect the transported inspection object Sm. For example, when a transmission type sensor is adopted, the item detection unit 22 is configured to include a light projector 22-1 and a light receiver 22-2. The light projector 22-1 and the light receiver 22-2 are disposed at positions sandwiching the transport unit 50 on the left and right. The height of the optical axis of the light projector 22-1 is adjusted in advance so that it is higher than the height of the surface of the transport unit 50 and lower than the height of the surface of the inspection object placed on the surface of the transport unit 50. The optical axis of the light projector 22-1 is directed to the right. The light projector 22-1 includes, for example, a light-emitting element (e.g., a light-emitting diode) that emits inspection light having a predetermined wavelength. The light receiver 22-2 includes a light-receiving element (e.g., an optical sensor) that receives light having that wavelength that is incident on the device itself. The photoreceiver 22-2 includes a light-receiving element that can receive the inspection light received from the projector 22-1. However, when the inspection object Sm crosses the optical axis of the projector 22-1, the inspection light is blocked by the left side surface of the inspection object Sm and does not reach the photoreceiver 22-2. The photoreceiver 22-2 generates a detection signal indicating the intensity of the received inspection light and outputs it to the inspection control unit 10.

[0019] When the intensity of the detection signal is higher than a predetermined intensity threshold, it indicates a state in which an article is not detected (non-detected), and when the intensity is lower than the predetermined intensity threshold, it indicates a state in which an article is detected (detected). The detection signal can serve as trigger data for acquiring measurement data from the measurement unit 24 and image data from the photographing unit 26. In other words, the article detection unit 22 functions as a trigger sensor. In the following description, the optical axis of the projector 22-1 may be referred to as the "article detection axis." As long as the item detection unit 22 can detect the transported inspection object Sm, it is not limited to the above-mentioned transmission-type photoelectric sensor, but may also be a diffuse reflection-type photoelectric sensor, or a non-contact sensor such as a capacitance sensor or laser sensor, or a sensor using a different measurement principle such as a contact sensor called a limit switch. However, since contact with a contact sensor can cause deviation in the direction of travel of the inspection object Sm thereafter and can also leave a contact mark on the inspection object Sm, it is preferable to use a non-contact sensor.

[0020] The measuring unit 24 measures the unevenness in a predetermined inspection area on the back surface of the inspection object. The number and arrangement of the measuring units 24 may vary depending on the number and positions of the inspection areas on the inspection object Sm, but it is preferable to have the same number of measuring units as the number of inspection areas. However, if the inspection areas are on the same axis in the transport direction, the number can be reduced to the number of coaxial lines. In the example shown in FIG. 1, the inspection system 1 is equipped with three measurement units 24-1 to 24-3. The measurement units 24-1 to 24-3 are supported by sensor support units 32-1 to 32-3, respectively, and are movable left or right. The sensor support units 32-1 to 32-3 function as measurement position adjustment units that adjust the positions of the measurement units 24-1 to 24-3 in a direction (y direction) intersecting the transport direction. The positions of the corresponding measurement units 24-1 to 24-3 may be set in advance for each inspection area so that the center of the measurement unit in the y direction coincides with the position of the measurement point. After detecting the inspection object Sm, the measurement units 24-1 to 24-3 are able to measure the unevenness on the back surface of the inspection object Sm.

[0021] Known distance measuring sensors can be used as the measurement sensors of the measurement units 24-1 to 24-3. For example, a laser distance meter can be used. In addition, the measurement units 24-1 to 24-3 are not limited to laser distance meters, and may use any measurement principle, such as a laser displacement sensor with a built-in camera or an ultrasonic distance sensor, as long as they can detect the unevenness of the Sm of the object to be inspected, i.e., the distance from the sensor to the inspection area.

[0022] When laser distance meters are used as the measurement units 24-1 to 24-3, their optical axes are oriented vertically. For example, such laser distance meters include a light emitter, a light receiver, and a detector. The light emitter emits laser light. The light receiver receives the reflected light of the laser light incident on the back surface of the inspection target Sm. The detector detects the phase difference between the laser light emitted by the light emitter and the reflected light received by the light receiver, and can measure the optical path length from the light emitter to the light receiver based on the detected phase difference, that is, the distance from the light emitter or the light receiver to the inspection position on the back surface of the inspection target Sm. The measured distance corresponds to the unevenness. The measurement units 24-1 to 24-3 output measurement data indicating the measured height to the inspection control unit 10. The height measurement may be performed while the inspection object Sm is being transported, or the transport device may be stopped at a predetermined timing and measurement may be performed. Since the measurement time can be shortened, it is preferable to measure while transporting the inspection object Sm.

[0023] Next, the inspection area of ​​the inspection object Sm will be described. In this embodiment, an in-mold bead foam product is the main inspection object Sm. In-mold bead foam products are used as containers for keeping food products, such as seafood, fresh produce, and frozen foods, cold or warm. In-mold bead foam products are obtained using bead expansion, a method of molding expandable raw materials. The beads used in bead expansion are small-diameter resin particles impregnated with a physical foaming agent such as hydrocarbon. Synthetic resins such as polystyrene and polyolefins (polypropylene and polyethylene) are used as raw materials. The beads are expanded by heating, and the expanded beads are sealed into the molding chamber mc14 of a mold installed in a molding machine from the fixed side mc10, as illustrated in FIG. 3. The mold has a concave middle mold mc12 and a convex middle mold mc52, which overlap to form the molding chamber mc14. The concave middle mold mc12 and the convex middle mold mc52 are installed on the fixed side mc10 and the movable side mc50, respectively. The concave middle mold mc12 and the convex middle mold mc52 are supported by frames mc16 and mc56 via inside plates mc18 and mc58, respectively, and are pressed together to form the molding chamber mc14. The filler mc36 is attached to the frame mc16 via a filler mounting flange mc38, and the foamed beads that serve as the raw material are filled into the molding chamber mc14 via the filling port fd.

[0024] The frame mc16 of the fixed side mc10 and the frame mc56 of the moving side mc50 are provided with back plates mc20 and mc70, respectively. The frame mc16, which forms chambers mc24 and mc74 between the concave middle die mc12 and the convex middle die mc52, is provided with a steam inlet mc26 and a cooling water inlet mc28, respectively, through which steam is introduced into chamber mc24 and cooling water is introduced into the cooling water piping inside chamber mc24. The frame mc16 is provided with a drain mc30, which exhausts steam from chamber mc24. Similarly, the frame mc56 is provided with a steam inlet mc76 and a cooling water inlet mc78, which respectively introduce steam into chamber mc74 and cooling water into the cooling water piping mc90 inside chamber mc74. The frame mc56 is provided with a drain mc80, which exhausts steam from chamber mc74. This adjusts the temperature of the mold. A mold release pin mc34 is attached to the frame 16 via a pin holder mc32. When the mold release pin mc34 is pushed from the fixed side mc10 to the moving side mc50, its tip applies a force to the moving side mc50 via the surface of the in-mold bead foam product formed in the molding chamber mc14, and the convex middle die mc52 fixed to the moving side mc50 moves away from the concave middle die mc12. This allows the in-mold bead foam product molded in the molding chamber mc14 to be removed.

[0025] With this mold configuration, the in-mold bead foam product (Sm) to be inspected tends to have a filling port mark fn at the position where the filling port of the filler mc36, which fills the molding chamber mc14 with raw material, and a pin mark pn at the position where the release pin contacts the surface of the fixed side mc10 (see Figure 4). The pin mark pn tends to appear as a concave abnormality, where the material sinks below the surrounding reference surface rs (see Figures 5 and 6). The filling port mark fn can also appear as a convex abnormality, where the material protrudes above the surrounding reference surface rs, or as a concave abnormality (see Figures 5 and 7). This filling port mark fn can also occur if the filler mc36 is not properly fixed in place relative to the back plate mc20 by the filler mounting flange mc38, or if the filler mc36 shifts position during molding. Additionally, an overfilling abnormality can occur around the filling port fd due to excessive injection of raw material. Therefore, in this embodiment, the area that was in contact with the filling port fd and the release pin mc is predetermined as the inspection position, and a state in which the unevenness from the reference surface is within a predetermined tolerance range is judged as pass (OK), and a state outside the tolerance range is judged as fail (NG) (see Figures 6 and 7).

[0026] As described above, the inspection system 1 may include, as another inspection means, for example, the photographing unit 26 (including the image analysis unit 130) that determines whether or not there is an abnormality in the surface state. The photographing unit 26 photographs an image of the surface of the inspection target Sm. In the example shown in Fig. 1, the inspection system 1 is provided with one photographing unit 26 closer to the x-direction than the measuring unit 24 and at a position higher than the transport unit 50.

[0027] For example, when detecting an abnormality (foreign matter) inside an in-mold bead foam product, the photographing direction of the photographing unit 26 is oriented vertically. The height of the photographing unit 26 is adjusted in advance so that the field of view of the photographing unit 26 includes the entire surface of the inspection object Sm. However, if the required resolution can be obtained, a method can also be adopted in which the height of the photographing unit 26 is fixed so that the largest inspection object Sm can be photographed, and when photographing a smaller inspection object Sm, the height of the photographing unit 26 is not adjusted, and the photographing position of the inspection object Sm is adjusted so that the inspection object Sm is positioned as close to the center of the photographing unit 26 as possible.

[0028] Furthermore, when detecting abnormalities in printed or affixed labels on the exterior of an in-mold bead foam product, the imaging direction of the imaging unit 26 is set in the y direction (and also in the reverse y direction if there is printing or labels on both sides) so that the processed surface of the inspection object Sm can be photographed. The distance between the imaging unit 26 and the inspection object Sm is adjusted in advance so that the field of view of the imaging unit 26 includes the entire printed or affixed surface of the inspection object Sm. However, if the required resolution can be obtained, a method can be adopted in which the distance from the imaging unit 26 is fixed so that the largest inspection object Sm can be photographed, and when photographing smaller inspection objects Sm, the distance from the imaging unit 26 is not adjusted, and the imaging position of the inspection object Sm is adjusted so that the inspection object Sm is positioned as close to the center of the field of view of the imaging unit 26 as possible. Furthermore, to optimize the distance between the imaging unit 26 and the inspection object Sm, the imaging unit 26 may be centered in the y direction or moved closer to one end of the conveying unit 50 rather than the center.

[0029] The photographing of the inspection object Sm in the photographing unit 26 may be performed while the inspection object Sm is being transported, or may be performed after the inspection object Sm is stopped by providing a stopper 56. However, to photograph a moving object being transported while ensuring a predetermined resolution, it is necessary to photograph it at a fast shutter speed. This requires the use of a lens with a bright aperture value, which is generally expensive, or increasing the sensitivity, which is generally considered to reduce resolution. For this reason, it is preferable to photograph the inspection object Sm while it is stopped. When the function of the stopper 56 is enabled, the position of the imaging unit 26 may be adjusted so as to include the entire surface of the inspection object Sm stopped by the stopper 56. In this case, the movement of the inspection object Sm stops, and a stable image can be obtained.

[0030] The photographing unit 26 outputs image data representing the photographed image to the image analysis unit 130 of the inspection control unit 10. The photographing unit 26 includes, for example, a digital camera. Here, the digital camera includes an imaging element having a two-dimensional array of multiple pixels (e.g., a charge-coupled device (CCD) sensor, a complementary metal-oxide-semiconductor (CMOS) sensor, etc.) and has a function of sending the photographed image as digital data to the image analysis unit 130. The digital camera may be a dedicated photographing device or a general-purpose photographing device commonly available as a peripheral device for personal computers, such as a USB camera, a web camera, or a network camera, as long as it has the resolution required for the image analysis unit 130 to make a judgment. One frame of an image photographed by the digital camera is represented by, for example, signal values ​​based on the intensities of the three primary colors of light exposed to each element within a predetermined period (photographing period), and is sent to the inspection control unit 10. The photographing section 26 may be set as to whether or not photographing is necessary in accordance with photographing necessity information input from the image analysis section 130. Whether or not image data is output from the photographing section 26 is controlled by setting as to whether or not photographing is necessary.

[0031] The image analysis unit 130 functions as a determination unit that determines the surface condition of the inspection object Sm based on image data input from the imaging unit 26. When imaging necessity information indicating the necessity of imaging is set, the image analysis unit 130 determines whether an abnormality has been detected on the surface of the inspection object Sm by referring to the image data input from the imaging unit 26. The image analysis unit 130 can detect the start of detection of the inspection object Sm by monitoring the detection signal input from the item detection unit 22 via the input / output unit 150. When imaging time information indicating the imaging start time is set, the image analysis unit 130 can determine the time when the inspection object Sm is detected as the reference time and the time after the imaging start time has elapsed from the reference time as the imaging start time. The image analysis unit 130 performs known image recognition processing on the image of the inspection object Sm shown in the image data input from the imaging unit 26 immediately after the imaging start time to determine the location and type of abnormality. As described above, the image analysis unit 130 can compare the image of the inspection object Sm with a master image previously set for each pair of the abnormality location and type to determine whether an abnormality has occurred for that pair.

[0032] The image analysis unit 130 may use a learning model (AI (Artificial Intelligence) learning model) such as a neural network to calculate a reliability indicating the possibility that each type of abnormality has occurred, and identify a region where the reliability is higher than a predetermined reliability as an abnormal region. If there is no region where the reliability is higher than the predetermined reliability, the image analysis unit 130 can determine that the type of abnormality has not occurred. If no type of abnormality has occurred, the image analysis unit 130 can determine that there is no abnormality.

[0033] The image analysis unit 130 may temporarily stop the operation of the transport unit 50 so that the stop period includes the imaging period for capturing one frame. In this case, the image analysis unit 130 stops the operation of the transport unit 50 at the imaging start time, which is a preset imaging start time after the reference time, instructs the imaging unit 26 to capture images, acquires image data, and then resumes the operation of the transport unit 50. The image analysis unit 130 may protrude the stopper 56 without stopping the operation of the transport unit 50, or may protrude the stopper 56 simultaneously with stopping the operation of the transport unit 50. This allows the movement of the inspection target Sm to be imaged to be stopped. The image analysis unit 130 outputs surface condition information indicating the presence or absence of an abnormality, and if an abnormality is present, the type of abnormality and the abnormal location to the item removal control unit 132.

[0034] The types of abnormalities to be detected include, for example, foreign matter adhesion, dirt adhesion, shrinkage, expansion, defects, holes, and hole blockage. Foreign matter adhesion primarily refers to the adhesion of solid objects of a certain size. Examples of solid objects that can be detected include bolts, washers, nuts, rusted metal, mold parts, or parts thereof. Dirt adhesion primarily refers to the adhesion of fluids, powders, particles, etc., such as sewage, oil, and component residue. Shrinkage refers to a decrease in the external dimensions from the design values. Expansion refers to an increase in the external dimensions from the design values. Target values ​​for the external dimensions or shape of the inspection object Sm may be preset in the image analysis unit 130 to determine whether or not there is shrinkage. Defects refer to missing or depressed portions of the inspection object Sm. Target values ​​for the external shape of the inspection object Sm may be preset in the image analysis unit 130 to determine whether or not there is a defect. Holes refer to openings (holes) in locations not intended by the design (see FIG. 5). Hole blocking refers to a state in which an opening (hole) that should be formed according to the design is blocked.

[0035] The discharge detection unit 28 detects the completion of discharge of the inspection object Sm from the conveying unit 50. The discharge detection unit 28 may be configured to include a sensor similar to that of the item detection unit 22, except that it is installed at the other end (exit) of the conveying unit 50. In the illustrated example, the discharge detection unit 28 includes a light-emitting unit 28-1 and a light-receiving unit 28-2. The description of the item detection unit 22 is cited for the functions and positional relationship between the light-emitting unit 28-1 and the light-receiving unit 28-2. The light-receiving unit 28-2 outputs a detection signal indicating the intensity of the inspection light received from the light-emitting unit 28-1 to the inspection control unit 10. As will be described later, the detection signal from the discharge detection unit 28 is used to detect the completion of discharge of the inspection object Sm, which is a non-defective product, from the conveying unit 50. After it is determined that discharge is complete, the stopper 56 member is protruded until the next inspection object Sm is determined to be a non-defective product. This prevents the item removal unit 40 from discharging a defective product from the conveying unit 50 and discharging a non-defective product immediately before it. The discharge detection unit 28 may be omitted.

[0036] If the inspection control unit 10 determines that the inspection object Sm has irregularities or an abnormality in its appearance after inspection as necessary, the item removal unit 40 removes the inspection object Sm from the conveyance path without sending it to a subsequent stage. The item removal unit 40 may be located to the side of the measurement unit 24 or the photographing unit 26 so as to remove the inspection object Sm, or may be located to the side after the inspection object Sm has passed the discharge detection unit 28. However, there may be limited space to the side of the measurement unit 24 or the photographing unit 26 due to equipment arrangement, or when photographing using the photographing unit 26, the photographing unit 26 may be housed in a dark box structure to stabilize the ambient light. In consideration of such cases, it is preferable to install the item removal unit 40 ahead of the measurement unit 24 or the photographing unit 26. The direction from which the inspection object Sm is discharged may be to the right or left of the conveyance direction depending on the equipment arrangement and surrounding conditions.

[0037] In the example shown in FIG. 1, the item removal unit 40 is located forward of the item detection unit 22 and installed to the right of the conveying unit 50. The item removal unit 40 removes inspection objects Sm determined to be defective from the conveying unit 50. The item removal unit 40 is, for example, an air injector. The air injector has a nozzle (not shown) and is installed with the nozzle facing left. When an exclusion command is input from the inspection control unit 10, the air injector sprays compressed air from the nozzle to the left. The inspection object Sm that receives the sprayed air moves leftward and is removed to a collection box (not shown) installed to the left of the conveying unit 50. The spray time for spraying air at one time is set to be sufficiently shorter than the time it takes for the transported inspection object to pass in front of the nozzle.

[0038] The object removal unit 40 is not limited to an air injector, but may also be an extruder (pusher) or a robot arm. The extruder includes a bar material with its longitudinal direction oriented in the y direction and a cylinder. The bar material is brought into contact with an inspection object Sm determined to be defective, and the cylinder drives the bar material in the y direction to push out the inspection object Sm. The robot arm includes a suction pad at its tip, which picks up an inspection object Sm determined to be defective and releases the suction after moving the tip. Air injection eliminates the need to consider the time required to restore the position of the bar material or robot arm, thereby eliminating loss of inspection efficiency (sometimes referred to as "tactile loss" in this application).

[0039] The item removal control unit 132 of the inspection control unit 10 identifies the discharge time indicated in the discharge time information set in the item removal control unit 10 and the spray time indicated in the spray time information. The item removal control unit 132 monitors the item detection data input from the item detection unit 22 via the input / output unit 150 and determines whether the inspection object Sm has been detected. The item removal control unit 132 determines that the inspection object Sm is a non-defective item when the determination result information input from the state determination unit 126 indicates a pass at all inspection positions and the surface state information input from the image analysis unit 130 indicates no abnormalities. An inspection object Sm determined to be a non-defective item is not removed from the transport unit 50.

[0040] The item removal control unit 132 determines that the inspection object Sm is defective when the determination result information input from the state determination unit 126 indicates failure at at least one inspection position or when the surface condition information input from the image analysis unit 130 indicates an abnormality. The item removal control unit 132 causes the item removal unit 40 to remove the inspection object Sm determined to be defective. Here, the item removal control unit 132 sets the time when detection of the inspection object Sm begins as a reference time, and when a time equivalent to the discharge time has elapsed from the reference time and the current time reaches the discharge time, outputs an exclusion command to the item removal unit 40 instructing it to spray air for a specified spray time. The item removal control unit 132 causes the item removal unit 40 to spray air. The inspection object Sm is removed by receiving the sprayed air flow. The item removal control unit 132 may output pass / fail information indicating whether the inspection object Sm is good or bad to the display control unit 134. The item removal control unit 132 may further output the determination result information and surface condition information to the display control unit 134.

[0041] The item removal control unit 132 monitors the detection signal input from the discharge detection unit 28, and can detect the completion of discharge of the inspection object Sm when the intensity of the detection signal remains higher than a predetermined intensity threshold for a predetermined time (the time during which the inspection object Sm passes) and then drops below the predetermined intensity threshold. When detecting the completion of discharge of the inspection object Sm, the item removal control unit 132 may protrude the member of the stopper 56 into the conveying unit 50. The item removal control unit 132 may release the protrusion of the member of the stopper 56 when the inspection object Sm is next determined to be a non-defective item. In this way, when the inspection object Sm is determined to be a non-defective item, the protrusion of the stopper 56 is released, and the inspection object Sm is discharged from the other end of the conveying unit 50, and the stopper 56 protrudes once discharge is complete. This prevents simultaneous discharge of an inspection object Sm determined to be defective and an inspection object Sm previously determined to be non-defective, and the inspection object Sm determined to be non-defective is discharged individually.

[0042] The operation panel 45 displays an operation screen and enables the setting of various parameters related to the operation of the inspection system 1. The operation screen includes configurable items and the setting contents of each item. The operation panel 45 includes, for example, a touch panel. The touch panel is configured by overlapping a display and a touch sensor. The display displays the operation screen based on operation screen data input from the inspection control unit 10. The touch sensor accepts user operations and outputs operation signals instructed by the accepted operations to the inspection control unit 10. The parameters are instructed by the operation signals. Note that the operation panel 45 may be omitted. As will be described later, the parameter setting unit 124 may display a setting screen on the display unit 160 and set various parameters based on operation signals input from the operation unit 170.

[0043] The transport unit 50 transports the inspection object Sm placed on its surface at a substantially constant speed in the x direction. By transporting the inspection object Sm at a constant speed, the measurement start time and measurement time for the inspection area can be accurately determined. In other words, if no information is set, the measurement unit 24 cannot determine whether the part to be measured at that time is the inspection area or another part. However, by setting the measurement start time and measurement time in advance, the inspection area can be identified based on the elapsed time from the reference time.

[0044] The transport unit 50 includes two guide rails 52 and multiple transport rollers 54. The two guide rails 52 are installed with their respective longitudinal directions facing the x direction and spaced apart in the y direction. The multiple transport rollers 54 each have their longitudinal directions facing the y direction, and both ends are fixed to the guide rails 52. Each transport roller 54 rotates around a rotation axis facing the y direction, thereby moving the inspection object Sm placed thereon in the x direction. A rubberized roller may be used as the conveying roller 54. A rubberized roller is a roller whose side is covered with a rubber film. This prevents the inspection target Sm from bouncing or slipping off the conveying roller 54. The conveying roller 54 may be provided with a rotation mechanism, and the presence or absence of rotation and the rotation speed may be controlled.

[0045] The stopper 56 is installed along the y-direction at the other end (exit) of the conveying section 50. When the function of the stopper 56 is enabled, the movement of the inspection object Sm may be controlled by one or both of the image analysis unit 130 and the item removal control unit 132, as described below. The stopper 56 has a long, narrow plate material with one side longer than the other side. The long side engages with the other end of the conveying section 50 as a rotation axis, and the orientation of the short side is variable around the rotation axis parallel to the y-direction. When the short side is oriented in the z-direction or closer to the z-direction than the x-direction, the plate material protrudes, thereby preventing the movement of the inspection object Sm. When the short side is oriented in the x-direction or closer to the x-direction than the z-direction, the protrusion of the plate material is released, so the movement of the inspection object Sm is not prevented, and the function of the stopper 56 is disabled. The stopper 56 has a fixture for fixing the orientation of the plate material.

[0046] The configuration of the stopper 56 is not limited thereto, and any configuration may be used as long as it can control whether or not the movement of the test object Sm needs to be stopped. The stopper 56 may be a cylinder whose longitudinal direction is oriented in the y direction and whose width is in the z direction, forming a so-called L-shaped angle, which is engaged with the other end of the conveying unit 50 so as to be movable in the z direction. Increasing the height of the cylinder causes it to protrude from the other end of the conveying unit 50, thereby stopping the movement of the test object Sm, and lowering the height of the cylinder releases the protrusion, thereby allowing the movement of the test object Sm. Alternatively, the stopper 56 may include a bar member and a cylinder whose longitudinal direction is oriented in the y direction, and the cylinder may allow the bar member to move in the y direction. Protruding the bar member into the conveying unit 50 stops the movement of the test object Sm, and releasing the protrusion of the bar member allows the movement of the test object Sm.

[0047] The position of the stopper 56 does not necessarily have to be fixed to the other end of the conveying unit 50. For example, the position of the stopper 56 may be adjustable in the x direction. In this case, the position at which the inspection object Sm is stopped varies in the x direction depending on the position of the stopper 56. Therefore, the position of the stopper 56 is set so that the entire inspection object Sm is included in the field of view of the imaging unit 26. The image analysis unit 130 is set to the imaging start time as the elapsed time from the reference time at which detection of the object to be detected begins until the tip of the inspection object Sm arrives at the position of the stopper 56. When the elapsed time from the reference time becomes the imaging start time, the image analysis unit 130 protrudes a member (e.g., a bar material) of the stopper 56 and acquires image data representing the image captured by the imaging unit 26. This enables stable analysis of inspection objects Sm of different sizes and shapes using images captured in a stationary state.

[0048] Alternatively, multiple stoppers 56 may be installed at different positions in the x direction. In this case, the image analysis unit 130 protrudes one of the stoppers 56 and does not protrude the other stoppers 56 in response to the arrival of the inspection object Sm. Therefore, the position at which the inspection object Sm stops in the x direction can be varied depending on the stopper 56 that protrudes its component. Therefore, a stopper 56 that protrudes its component so that the entire inspection object Sm is included in the field of view of the imaging unit 26 is preselected. The selected stopper 56 and the elapsed time from the reference time at which detection of the object begins until the tip of the inspection object Sm arrives at the position of the selected stopper 56 are set in the image analysis unit 130 as the imaging start time. When the elapsed time from the reference time corresponds to the imaging start time, the image analysis unit 130 protrudes the component of the set stopper 56 and acquires image data representing the image captured by the imaging unit 26. This also enables stable analysis of inspection objects Sm of different sizes and shapes using images captured in a stationary state.

[0049] An automatic alignment machine (e.g., Patent No. 4319311) may be installed adjacent to one end (entrance) of the transport unit 50 in the reverse x direction, and the inspection objects Sm may be transported therein. The automatic alignment machine adjusts the orientation of the inspection objects Sm so that one side (e.g., short side) of the approximately rectangular parallelepiped shape faces the x direction. A stacker (not shown) may be installed adjacent to the other end (exit) of the transport unit 50 in the x direction, and the inspection objects Sm may be transported therein. Additionally, the inspection system 1 may be equipped with a light (not shown) that irradiates the surface of the inspection target Sm with light, or a light shielding plate (not shown) that blocks external light. This emphasizes abnormalities and reduces false detections due to external light. The light shielding plate may be installed in any position or orientation and may emit light with any spectrum, as long as it can emphasize abnormalities. The light shielding plate may completely block light or may be polarized.

[0050] Next, an example of the functional configuration of the inspection control unit 10 according to this embodiment will be described. Fig. 2 is a schematic block diagram showing an example of the functional configuration of the inspection control unit 10 according to this embodiment. The test control unit 10 includes an operation control unit 120, a storage unit 140, an input / output unit 150, a display unit 160, and an operation unit 170.

[0051] The operation control unit 120 performs processing for implementing the functions of the inspection control unit 10 and processing for controlling those functions. The operation control unit 120 may be configured with a dedicated component, or may include a processor such as a CPU (Central Processing Unit). A general-purpose control device such as a programmable logic controller (sometimes referred to herein as a "PLC (Programmable Logic Controller)") or a personal computer may be used. The processor reads a program pre-stored in the storage unit 140 and executes the read program to implement the functions of the operation control unit 120. In this application, "executing a program" or "executing a program" means executing processing instructed by various commands written in the program.

[0052] The storage unit 140 stores various data and programs. The storage unit 140 stores data (including parameters and setting information) used for various processes in the operation control unit 120 and data acquired by the operation control unit 120. The storage unit 140 includes a storage medium (sometimes referred to as "memory" in this application) such as a RAM (Random Access Memory) or a ROM (Read-Only Memory). The input / output unit 150 can input and output various types of data to and from other devices wirelessly or via a wired connection. The input / output unit 150 is, for example, an input / output interface. The input / output unit 150 may be connected to a communication network via a wired or wired connection, and may be connected to other devices connected to the communication network wirelessly or via a wired connection, and may input and output various types of data such as measurement data from the measurement unit 24 and image data from the imaging unit 26. The input / output unit 150 may be a known communication interface that complies with standards such as JIS RS232C, JIS RS422, or GP-IB (General Purpose Interface Bus).

[0053] The display unit 160 displays characters, symbols, images, or a combination thereof in accordance with various display data output from the operation control unit 120. The display unit 160 is, for example, a display. The display unit 160 may include a speaker and be capable of reproducing audio based on an audio signal output from the operation control unit 120 (which may be the audio signal itself, or, if the display unit 160 has a storage function, may be a number designation signal that designates a code number for reproducing audio data associated with a pre-stored code number).

[0054] The display control unit 134 of the inspection control unit 10 controls the display of information on the operation panel 45 and the display unit 160. The display control unit 134 outputs, for example, operation screen data showing an operation screen to the operation panel 45. The operation panel 45 displays the operation screen based on the operation screen data acquired from the display control unit 134. The display control unit 134 sequentially counts the number of times that good or defective products have occurred based on the pass / fail information input from the item removal control unit 132. When the number of times that consecutive defective products have occurred exceeds a preset limit value for the number of consecutive defective determinations, the display control unit 134 generates a warning screen showing warning information indicating the occurrence of defective products, and outputs the warning screen data to the display unit 160 or the operation panel 45. An operator who sees the warning screen displayed on the display unit 160 or the operation panel 45 is notified that a number of abnormalities has occurred in the inspection object Sm that exceeds the limit value. By being notified of the occurrence of consecutive defective products, the operator can immediately notice a problem in an upstream process (for example, a production process).

[0055] The display control unit 134 may generate an inspection result screen showing the inspection results based on the pass / fail information input from the item removal control unit 132, and output inspection result screen data showing the inspection result screen to the display unit 160 or the operation panel 45. The display unit 160 or the operation panel 45 displays the inspection result screen based on the inspection result screen data input from the display control unit 134. The display control unit 134 may generate an inspection result screen that includes the determination result information and surface condition information input from the item removal control unit 132. The display control unit 134 may generate an inspection result screen that further includes an image of the inspection object Sm shown in the screen data input from the imaging unit 26. The display control unit 134 may generate an inspection result screen, for example, by superimposing a character string indicating the type of abnormality and a symbol indicating the abnormal portion on the image of the inspection object Sm.

[0056] The operation unit 170 receives a user operation, generates an operation signal in response to the received operation, and outputs the generated operation signal to the operation control unit 120. The operation unit 170 is, for example, a touch sensor. The display constituting the display unit 160 and the touch sensor constituting the operation unit 170 may be superimposed on each other to form a touch panel. When the inspection control unit 10 is connected to an operation panel 45, the display unit 160 and the operation unit 170 may be omitted. Conversely, when the inspection control unit 10 has the functions of the display unit 160 and the operation unit 170, the operation panel 45 may be omitted.

[0057] The operation control unit 120 includes a parameter setting unit 124, a state determination unit 126, an image analysis unit 130, an item removal control unit 132, and a display control unit 134. The parameter setting unit 124 outputs operation screen data to the operation panel 45 via the input / output unit 150, causing the operation screen to be displayed. The parameter setting unit 124 sets parameters used for detection in accordance with the operation data input from the operation panel 45 via the input / output unit 150. The parameter setting unit 124 can set, for example, the following parameters: (1) start time, (2) measurement time, (3) tolerance range, (4) discharge time, (5) injection time, (6) limit value for the number of consecutive defective judgments, (7) whether photography is required, and (8) stopper effectiveness.

[0058] The start time corresponds to the time from the reference time when the detection of the inspection object starts to the time when the front end of the inspection area passes the x-coordinate of the measurement units 24-1 to 24-3, and is set for each inspection area (see FIG. 1). The measurement time corresponds to the time from the time when the front end of the inspection area passes the article detection axis to the time when the rear end of the inspection area passes the x-coordinate of the measurement units 24-1 to 24-3, and is set for each inspection area. As described above, height measurement is performed while the inspection object Sm is moving. Since the start time and measurement time provide clues to the inspection position, the parameter setting unit 124 functions as a measurement position adjustment unit that identifies the inspection area to be measured in the transport direction (x-direction). The allowable range is the range allowed for height in the inspection area. The allowable range is expressed by an upper limit and a lower limit, and is set for each inspection area (see FIGS. 6 and 7).

[0059] The ejection time corresponds to the time from the reference time when detection of the object begins to the time (ejection time) when the ejection of the inspection object Sm determined to be defective due to an abnormality or irregularity based on the captured image begins. The image capture begins when a preset image capture start time has elapsed from the reference time. The ejection time may be set, for example, to a time delayed by a predetermined time (ejection time) from the time when an abnormality or irregularity based on the image is determined. The ejection time may be defined as the elapsed time from the reference time when detection of the object begins, as described above, or as the elapsed time from the image capture time. The ejection time may be set to 0 seconds or omitted. The injection time is the time required for the object removal unit 40 to eject air to remove the inspection object Sm. The limit value for the number of consecutive defective judgments is the upper limit of the number of times the inspection object Sm is allowed to be consecutively judged to be defective. The necessity of image capture indicates whether or not the image capture unit 26 needs to capture an image. Examples of parameter settings will be described later. The stopper validity is information indicating whether the function of the stopper 56 is valid. When the stopper validity indicates that the function of the stopper 56 is valid, the photographing time may also be set. As the photographing time, the elapsed time from the time when the front end of the inspection area passes the item detection axis to the time when the front end of the inspection target Sm comes into contact with the stopper 56 may be set.

[0060] The parameter setting unit 124 sets, in the state determination unit 126, inspection parameter information indicating the start time, measurement time, and tolerance range for each inspection position (inspection area). The parameter setting unit 124 sets, in the item removal control unit 132, discharge time information indicating the discharge time and spray time information indicating the spray time. The parameter setting unit 124 sets, in the display control unit 134, consecutive defective judgment count setting information indicating the consecutive defective judgment count limit value. The parameter setting unit 124 sets imaging necessity information indicating whether imaging is necessary or not in the image analysis unit 130. The parameter setting unit 124 may set the imaging necessity information in the imaging unit 26. When the function of the stopper 56 is enabled and the shooting time is set, the parameter setting unit 124 may set the shooting time information indicating the shooting time in the image analysis unit 130 .

[0061] The state determination unit 126 functions as a determination unit that determines the state of unevenness at each corresponding measurement position based on the measurement data input from the measurement units 24-1 to 24-4. The state determination unit 126 monitors the item detection data input from the item detection unit 22 via the input / output unit 150, and determines whether the inspection object Sm has been detected. The state determination unit 126 determines the time when detection of the inspection object Sm starts as a reference time, the time after the reference time has elapsed as a start time for the measurement, and specifies the measurement time for each inspection position. The start time and measurement time are specified for each inspection position from the inspection parameter information set in the state determination unit 126. The state determination unit 126 monitors the measurement data input from the corresponding measurement unit 24 via the input / output unit 150 during the measurement period from the measurement start time until the measurement time has elapsed, and monitors the state of height (unevenness) indicated in the measurement data for each inspection position. The status determination unit 126 determines an inspection position whose height falls within the allowable range during the measurement period as passing (OK), and determines an inspection position whose height exceeds the allowable range during the measurement period as failing (NG). The status determination unit 126 outputs determination result information indicating the determination result for each inspection position to the item removal control unit 132.

[0062] The state determination unit 126 may also detect macroscopic shape abnormalities (e.g., warpage) of the inspection target Sm from the measurement data input by any of the measurement units 24-1 to 24-3. "Warpage" refers to a shape change in which the edge of a plate-like portion is higher than the center. "Warpage" tends to occur when conditions such as temperature and pressure do not satisfy predetermined molding conditions. To detect "warpage," the start time is set to be immediately after the reference time, and the measurement time is set to the time required for the inspection target Sm to move its length in the x direction, or a time approximately equivalent to that time. The allowable range of height for warpage is set as the tolerance. If the height indicated by the measurement data is within the tolerance range, it is determined to be pass (OK), and if the height exceeds the tolerance range, it is determined to be fail (NG).

[0063] Next, an example of a setting screen according to this embodiment will be described. FIG. 9 is a diagram showing a first example of a setting screen according to this embodiment. In the setting screen shown in FIG. 9, the allowable height range (OK detection range) for each inspection position for the product name "AB9876" as the inspection target Sm is set. In the menu field on the bottom row, the setting for "Setting 02" out of four types of setting information "Setting 01" to "Setting 04" is indicated by a difference in brightness from its surroundings. Each inspection position is associated with "Sensor 01" and "Sensor 02" as the measurement units. The origin position indicates the height (z coordinate) of the reference plane. In this example, the upper and lower limits of the allowable range are set as absolute values ​​obtained by adding the height of the origin position.

[0064] Fig. 10 is a diagram showing a second example of a setting screen according to this embodiment. In the setting screen shown in Fig. 10, the allowable range of the inspection position corresponding to "sensor 03", the injection time (reject air time), the limit value of the number of consecutive defective judgments (number of consecutive NG alarms), the stopper validity (exit stopper valid 1, invalid 0), the discharge time (NG discharge time after camera photographing), and the photographing necessity information (camera photographing valid 1, invalid 0) are set as "setting 04".

[0065] Fig. 11 is a diagram showing a third example of a setting screen according to this embodiment. In the setting screen shown in Fig. 11, as "Setting 03," write necessity information (write, OFF, ON) for the inspection positions corresponding to "Sensor 01" to "Sensor 03," the start time, and the measurement time are set. "Write" indicates that the value input by operation is saved and reflected in the operation.

[0066] As described above, the inspection system 1 according to this embodiment includes a measurement unit (measurement units 24 (24-1 to 24-4)) that measures the surface irregularities in a predetermined inspection area of ​​a bead method foam molded product (in-mold bead foam product), and a judgment unit (state judgment unit 126) that determines whether the irregularities exceed a predetermined tolerance. The inspection area includes an area that was in contact with the filling port that supplies raw material to the mold (metal mold) used to mold the in-mold bead foam product. This configuration determines whether the unevenness at each local inspection position exceeds the tolerance. Concave and convex anomalies that tend to occur in the inspection area, which were previously easily overlooked, can be detected, allowing for accurate pass / fail judgment. Furthermore, by limiting the inspection area to a portion of the area where abnormalities tend to frequently occur in the bead-method foam molded article being inspected, the inspection load can be reduced.

[0067] The inspection system 1 may include a conveying unit 50 that conveys the bead method foam molded article in a predetermined conveying direction (x direction) at a predetermined conveying speed, and an article detecting unit 22 that detects the conveyed bead method foam molded article. The inspection system 1 may also include a measurement position adjusting unit (parameter setting unit 124, sensor support unit 32) that determines a measurement period (start time, measurement time) for unevenness based on the distance in the conveying direction from the tip of the bead method foam molded article to the inspection area and the conveying speed, and that can move the measurement unit in a direction intersecting the conveying direction to a position where unevenness can be measured during the measurement period. With this configuration, when the in-mold bead foam product being transported is detected, each inspection area moves to a position where the unevenness can be measured during the measurement period. Since it is possible to inspect the in-mold bead foam product during the transport process, the inspection can be carried out efficiently.

[0068] The inspection system 1 may include an article removal unit 40 that removes the bead method foam molded article from the conveying unit when the unevenness exceeds an allowable range. With this configuration, foam molded articles produced by the bead method whose irregularities exceed the allowable range are removed from the conveying section 50 as defective products, and non-defective products can be efficiently collected.

[0069] The inspection area may include a second area that was in contact with a mold release tool that releases the bead method foam molded article from the mold. The surface on which the first area that was in contact with the filling port that supplies raw material to the mold for molding the bead method foam molded article is located is the same as the surface on which the second area is located. This configuration contributes to economical realization because the inspection area is located on the same plane, and it is sufficient to place the measurement unit facing that plane. Also, since it becomes possible to use in-mold bead foam products molded by a molding machine in which the filling port and mold release tool are arranged on the same plane, filling and demolding with raw materials can be performed from that side, which reduces the complexity of the manufacturing process.

[0070] The measuring unit 24 may be a laser distance measuring device that measures the distance to the inspection area in a direction perpendicular to a reference plane that is parallel to the conveyance direction of the bead method foam molded article. This configuration allows the unevenness at the inspection position to be measured with high accuracy.

[0071] The inspection system 1 is equipped with an imaging unit 26 that captures an image of a surface (front surface) different from the surface (back surface) on which the inspection area is set, and the judgment unit (image analysis unit 130) may judge the state of the bead method foam molded body based on the image. With this configuration, an image of a surface other than the surface being measured for unevenness is captured, and the state of that surface is determined from the captured image. By performing unevenness measurement and state determination based on the image in parallel, the time required for inspection can be shortened.

[0072] The embodiments of the present invention have been described in detail above with reference to the drawings, but the specific configuration is not limited to that described above, and various design changes can be made within the scope of the gist of the present invention. [Explanation of symbols]

[0073] 1...inspection system, 10...inspection control unit, 22...item detection unit, 24...measurement unit, 26...photography unit, 28...discharge detection unit, 40...item removal unit, 45...operation panel, 50...conveyance unit, 52...guide rail, 54...conveyance roller, 56...stopper, 120...operation control unit, 124...parameter setting unit, 126...status determination unit, 130...image analysis unit, 132...item removal control unit, 134...display control unit, 140...storage unit, 150...input / output unit, 160...display unit, 170...operation unit

Claims

1. 1. A method in an inspection system, comprising: a first step in which a measurement unit measures the height of surface irregularities in a predetermined inspection area of ​​a bead method foam molded product; a second step in which the determination unit determines whether or not the height of the irregularities exceeds a predetermined allowable range, The inspection area includes an area that was in contact with a filling port that supplies raw material to a mold for forming the bead method foam molded article. Testing method.

2. a time for measuring the height of the irregularities is determined in advance based on the distance from the tip of the bead method foam molded article to the inspection area and a predetermined transport speed; the position of the measurement unit is adjusted in a direction intersecting a predetermined conveying direction to a position where the height of the unevenness can be measured at the measurement time; a third step in which an article detection unit detects the bead method foam molded article; a fourth step in which the conveying unit conveys the bead method foam molded article in the predetermined conveying direction at the predetermined conveying speed. The inspection method according to claim 1 .

3. and a fifth step in which an article removal unit removes the bead method foam molded article from the conveyance unit when the height of the irregularities exceeds the allowable range. The inspection method according to claim 2 .

4. The inspection area includes a second area that was in contact with a mold release tool that releases the bead method foam molded article from the mold. The inspection method according to any one of claims 1 to 3.

5. The surface on which the first region, which is the region in contact with the filling port for supplying raw materials to the mold for forming the bead method foam molded article, is arranged is the same as the surface on which the second region is arranged. The inspection method according to claim 4.

6. The measurement unit includes a laser distance measuring device that measures the distance to the inspection area in a direction perpendicular to a reference plane that is parallel to the conveyance direction of the bead method foam molded article. The inspection method according to any one of claims 1 to 5.

7. a sixth step in which an imaging unit captures an image of a surface different from the surface on which the inspection area is set; a seventh step in which the determination unit determines the state of the bead method foam molded article based on the image. The inspection method according to any one of claims 1 to 6.

8. an eighth step in which the article removal unit removes the bead method foam molded article, whose height of the irregularities is determined to exceed a predetermined tolerance range, as a defective product from the conveying unit that conveys the bead method foam molded article; a ninth step in which the display control unit presets a limit value for determining consecutive defects, and when the number of times the defective products are detected consecutively exceeds the limit value for determining consecutive defects, causes the display unit to display warning information. The inspection method according to any one of claims 1 to 7.

Images