Packaging device

Abstract

Provided is a packaging device for sequentially packaging a plurality of objects to be packaged conveyed from the upstream side to the downstream side in a conveyance direction. The packaging device comprises: an object-to-be-packaged supply part for sequentially supplying objects to be packaged; a bag-making part for making a cylindrical bag of a film by abutting both edge parts in the width direction of the film against each other so as to wrap each of the objects to be packaged being sequentially supplied by the object-to-be-packaged supply part; a first seal part for sealing both edge parts in the width direction of the film that have been abutted against each other by the bag-making part; a second seal part provided separately on the downstream side in the conveyance direction of the first seal part and which seals a part to be sealed between the objects to be packaged adjacent to each other with respect to the film; and a foreign object detector that detects a foreign object inside the film. The foreign object detector is disposed between the first seal part and the second seal part in the conveyance direction.

Description

[Technical Field]

[0001] The present invention relates to a packaging device that sequentially packages conveyed items to be packaged. [Background technology]

[0002] A known packaging device is, for example, that described in Patent Document 1. The packaging device in Patent Document 1 is equipped with a foreign object detector. The foreign object detector detects whether any foreign object is present in the packaging bag along with the packaged item. In the packaging device in Patent Document 1, the foreign object detector is provided downstream of the top seal section. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Japanese Patent Application Laid-Open No. 2006-298384 Summary of the Invention [Problem to be solved by the invention]

[0004] In the packaging device of Patent Document 1, the foreign object detector is installed downstream of the top seal portion. In other words, the foreign object detector is installed downstream of a conventional packaging device. This increases the overall length of the packaging device. On the other hand, it is desirable for the packaging device to be able to be installed in a smaller space. Therefore, it is desirable to prevent the overall length of the packaging device from increasing.

[0005] Therefore, the present invention aims to provide a packaging device that can prevent the overall length of the packaging device from increasing when a foreign object detector is incorporated into the packaging device, and that can detect foreign objects with high accuracy. [Means for solving the problem]

[0006] One aspect of the present invention is a packaging device that sequentially packages multiple packaged items transported from upstream to downstream in a conveying direction. This packaging device includes a packaged item supply unit, a bag making unit, a first sealing unit, a second sealing unit, and a foreign object detector. The packaged item supply unit sequentially supplies the packaged items. The bag making unit butts both widthwise edge portions together to form a tubular bag from film so as to enclose each of the packaged items sequentially supplied by the packaged item supply unit. The first sealing unit seals both widthwise edge portions of the film that have been butted together in the bag making unit. The second sealing unit is located downstream in the conveying direction from the first sealing unit and separates therefrom, and seals the sealed portions of the film between adjacent packaged items. The foreign object detector detects foreign objects in the film. This foreign object detector is located between the first sealing unit and the second sealing unit in the conveying direction.

[0007] According to one aspect of the present invention, by arranging the foreign object detector between the first sealing portion and the second sealing portion, it is possible to prevent the overall length of the packaging device from increasing. [Effects of the Invention]

[0008] According to the present invention, when a foreign object detector is incorporated into a packaging device, it is possible to prevent the overall length of the packaging device from increasing, and to detect foreign objects with high accuracy.

[0009] The above and other objects, features, and advantages of the present invention will become apparent from the following detailed description of preferred embodiments, which proceeds with reference to the accompanying drawings. [Brief explanation of the drawings]

[0010] [Figure 1] FIG. 1 is a front view showing a packaging device according to an embodiment of the present invention. [Figure 2] FIG. 2 is a plan view showing the packaging device of FIG. [Figure 3] 10 is a flowchart showing the procedure of a drive determination process executed by a control device of the packaging device of FIG. DETAILED DESCRIPTION OF THE INVENTION

[0011] A packaging device 1 according to an embodiment of the present invention will be described below with reference to the drawings. Note that the concept of direction used in the following description is used for convenience of explanation and does not limit the orientation of the configuration of the invention to that direction. Furthermore, the packaging device 1 described below is merely one embodiment of the present invention. Therefore, the present invention is not limited to the embodiment, and additions, deletions, and modifications are possible within the scope of the invention.

[0012] <Packaging equipment> The packaging device 1 shown in FIGS. 1 and 2 sequentially packages a plurality of packaged items 2 conveyed from the upstream side to the downstream side in the conveying direction. The packaging device 1 is, for example, a horizontal regular pillow packaging device. More specifically, the packaging device 1 sequentially packages a plurality of packaged items 2 conveyed in a conveying direction, which is one of the horizontal directions, in pillow bags 3. In this embodiment, the packaging device 1 individually packages the packaged items 2, such as food and other articles, in the pillow bags 3. Note that in the packaging device 1, the packaged items 2 packaged in the pillow bags 3 are not limited to a single item, but may also be a collection of multiple items. In other words, the pillow bags 3 may contain multiple items. The packaging device 1 mainly includes a film supply unit 11, a packaged item supply unit 12, a bag former 13, a center seal unit 14, a foreign object detector 15, and a top seal unit 16. The packaging device 1 also includes a center conveyor 17, an output conveyor 18, and a control device 19. The center conveyor 17 does not necessarily have to be provided.

[0013] <Film supply machine> The film supplying machine 11 supplies the film 4 for packaging the packaged items 2 to the bag former 13, which will be described in detail later. The film supplying machine 11 includes, for example, a film roll 21 and a feed roller 22. The film roll 21 is formed by winding the strip-shaped film 4 around a core material 21a. The feed roller 22 supplies the film 4 unwound from the film roll 21 to the bag former 13. More specifically, the feed roller 22 is rotationally driven by a drive motor (not shown). As a result, the feed roller 22 supplies the film 4 to the bag former 13.

[0014] <Packaged material feeding machine> Packaged item supply machine 12, which is an example of a packaged item supply section, sequentially supplies packaged items 2 to bag former 13. More specifically, packaged items 2 are sequentially placed on packaged item supply machine 12 at a predetermined timing. Packaged item supply machine 12 then transports the placed packaged items 2 in the transport direction and supplies them to bag former 13. Packaged item supply machine 12 is, for example, a belt conveyor.

[0015] <Bag making machine> As shown in FIG. 2 , the bag former 13, an example of a bag-making unit, butts both widthwise edge portions 4a of the film 4 together to form a tubular bag of film 4 so as to wrap each of the packaged items 2 sequentially supplied by the packaged item supply machine 12. More specifically, the film 4 passes through the bag former 13 from the film supply machine 11 and is sent to a center seal unit 14 located downstream of the bag former 13 in the conveyance direction. As the film 4 passes through the bag former 13, the bag former 13 forms the film 4 into a tubular bag. In this embodiment, the bag former 13 bends both widthwise edge portions 4a of the film 4 downward as it passes, thereby rolling the film 4. Furthermore, the bag former 13 places both widthwise edge portions 4a of the rolled film 4 into a slit 13a on its lower side and butts them together. This forms a tubular bag of film 4 with both widthwise edge portions 4a hanging downward. At this time, each of the packaged items 2 sequentially supplied by the packaged item supply machine 12 is fed into the film 4 being formed into a cylindrical shape. Therefore, the bag former 13 rolls up the film 4 so as to enclose the packaged items 2 being fed in, forming a cylindrical bag.

[0016] <Center seal> The center seal unit 14, an example of a first seal unit, seals both widthwise edge portions 4a of the film 4 that have been butted together in the bag former 13. More specifically, the center seal unit 14 heats and presses both widthwise edge portions 4a of the hanging film 4 as shown in FIG. 1 . More specifically, the center seal unit 14 sandwiches and heats both widthwise edge portions 4a from both sides in the width direction perpendicular to the conveyance direction. This causes both widthwise edge portions 4a to be heat-sealed to each other. Note that both widthwise edge portions 4a may also be configured to be pressure-bonded to each other with an adhesive or the like, as long as they are sealed to each other.

[0017] More specifically, the center seal section 14 includes a receiving plate 25 and multiple press roller mechanisms 26, 27. The receiving plate 25 allows the packaged items 2 wrapped in the tubular film 4 to flow downstream in the conveying direction on the receiving plate 25. The receiving plate 25 also has a slit 25a. The slit 25a extends in the conveying direction on the receiving plate 25 and is positioned to correspond to the slit 13a of the bag former 13. In this embodiment, both widthwise edge portions 4a are inserted into the slit 25a so as to be transferred from the slit 13a. When the tubular film 4 flows over the receiving plate 25 together with the packaged items 2, the widthwise edge portions 4a flow downstream in the conveying direction with hanging portions 4b protruding from the slit 25a.

[0018] The multiple press roller mechanisms 26, 27 seal the widthwise edge portions 4a by abutting them against each other and heat-pressing them. In this embodiment, the center seal unit 14 includes two press roller mechanisms 26, 27. The two press roller mechanisms 26, 27 are spaced apart in the conveyance direction of the backing plate 25 and positioned below the backing plate 25. More specifically, each press roller mechanism 26, 27 has a pair of roller units 26a, 27a. Each of the pair of roller units 26a, 27a is spaced apart in the widthwise direction across the slit 25a in a plan view and pressurizes and clamps the hanging portion 4b. The pair of roller units 26a, 27a is heated by a heater (not shown) and heat-presses the hanging portion 4b while clamping it. This seals the hanging portion 4b, forming a center seal 4d in the tubular film 4. Furthermore, the pair of roller units 26a, 27a are each provided with a drive motor 26b, 27b. Each of the pair of roller units 26a, 27a is driven to rotate by the drive motor 26b, 27b about an axis extending in the height direction. As a result, the center seal 4d is fed downstream in the conveyance direction by each of the pair of roller units 26a, 27a, i.e., the tubular film 4 is fed downstream in the conveyance direction. In this embodiment, the height direction is perpendicular to the conveyance direction and the width direction.

[0019] <Foreign object detector> The foreign object detector 15 detects foreign objects, including metal, inside the film 4 (in this embodiment, objects other than the packaged item 2 to be packaged). The detection method of the foreign object detector is appropriately selected from a coaxial or opposing type, a magnetized type, a magnetic bias magnetic field method, etc. The coaxial or opposing type is a method of detecting foreign objects by using a receiving coil to detect an electromagnetic field generated by a transmitting coil. The magnetized type is a method of detecting foreign objects by using a coil to detect a magnetic field generated by a magnetized foreign object when the foreign object approaches the coil. The magnetic bias magnetic field method is a method of detecting foreign objects by using a coil to detect changes in the magnetic field generated by a magnet when the foreign object approaches. In this embodiment, the foreign object detector 15 is a metal detector using a magnetic bias magnetic field method (for example, manufactured by Shinto Kogyo Co., Ltd.). Note that a metal detector using a magnetic bias magnetic field method can have only one gate for inspecting foreign objects. Furthermore, a metal detector using a magnetic bias magnetic field method can omit a power supply for driving the sensor module. Therefore, a magnetic bias magnetic field type metal detector can further reduce the overall length of the packaging device from increasing compared to other types of foreign object detectors, and can reliably detect foreign objects.

[0020] The foreign object detector 15 is disposed between the center seal unit 14 and the top seal unit 16, which will be described in detail later. In this embodiment, the foreign object detector 15 is disposed between the center seal unit 14 and the center conveyor 17, which will be described in detail later. The packaged items 2 are sent to the foreign object detector 15 from the center seal unit 14 along with the tubular film 4. The foreign object detector 15 switches its detection function on and off at a predetermined timing as each packaged item 2 passes. That is, the foreign object detector 15 turns its detection function on as the packaged item 2 begins to pass and turns its detection function off once the packaged item 2 has passed. Therefore, the detection function is turned off between adjacent packaged items 2. Because only the tubular film 4 is present between adjacent packaged items 2, there is a possibility of false detection due to noise caused by external disturbances. The foreign object detector 15 reduces the occurrence of false detection by turning its detection function off between adjacent packaged items 2. As described above, the foreign object detector 15 receives the packaged item 2 from the center seal section 14 together with the tubular film 4. Therefore, the timing at which the packaged item 2 passes through the foreign object detector 15 is predetermined, making it easy to turn the detection function on and off. The foreign object detector 15, which operates in this manner, includes a conveying path 31, a pair of magnetic bias sensors 32 and 33, a sensor frame 34, and a vibration isolation mechanism 35.

[0021] The conveying path 31 is interposed between the center seal unit 14 and the center conveyor 17. The conveying path 31 receives the packaged items 2 sent together with the tubular film 4 from the center seal unit 14. At this time, the center seal 4d hanging down from the slit 25a is folded in one direction or the other in the width direction and placed on the conveying path 31. The packaged items 2 are then flowed downstream in the conveying direction along the conveying path 31 together with the tubular film 4. The packaged items 2 are then transferred from the conveying path 31 to the center conveyor 17.

[0022] Each of the pair of magnetic bias sensors 32, 33 has a magnet and a coil (neither of which is shown). The pair of magnetic bias sensors 32, 33 are arranged spaced apart on either side of the conveying path 31. In this embodiment, the magnetic bias sensors 32, 33 are arranged spaced apart in the vertical direction on either side of the conveying path 31. However, the magnetic bias sensors 32, 33 are not necessarily limited to the arrangement described above, and may be arranged spaced apart in the width direction.

[0023] Furthermore, foreign object detector 15 does not necessarily need to include two magnetic bias sensors 32, 33, and may have only one magnetic bias sensor. In this case, the magnetic bias sensor is disposed, for example, above or below conveying path 31. One magnetic bias sensor may be configured by disposing a magnet on one side of conveying path 31 in the vertical direction and disposing a coil on the other side of conveying path 31 in the vertical direction.

[0024] The magnetic bias sensors 32 and 33 have a magnetic bias function that amplifies the magnetism of foreign objects. The magnetic bias sensors 32 and 33 also have a detection function that detects the presence or absence of foreign objects by detecting changes in the magnetic field lines caused by the foreign object passing through. That is, the pair of magnetic bias sensors 32 and 33 amplify the magnetism of foreign objects passing between them, and detect foreign objects by detecting changes in the magnetic field lines caused by the amplified magnetism.

[0025] The sensor frame 34 connects the pair of magnetic bias sensors 32, 33. The sensor frame 34 has high rigidity, allowing the pair of magnetic bias sensors 32, 33 to move integrally up, down, left, and right. The vibration isolation mechanism 35 suppresses vibrations transmitted from each seal portion 14, 16 to the pair of magnetic bias sensors 32, 33. More specifically, the pair of magnetic bias sensors 32, 33 are mounted on the frame (not shown) of the packaging device 1 via the vibration isolation mechanism 35. The vibration isolation mechanism 35 is composed of vibration isolation rubber, dampers, etc., and suppresses vibrations generated in various parts of the packaging device 1 from being transmitted from the frame to each of the magnetic bias sensors 32, 33.

[0026] <Center conveyor> The center conveyor 17, an example of a first conveyor, is disposed between the center seal 14 and the top seal 16, which will be described in detail later, in the conveying direction. In this embodiment, the center conveyor 17 is disposed between the foreign object detector 15 and the top seal 16. The center conveyor 17 conveys the packaged items 2, which are to be packaged in the film 4 sealed by the center seal 14, to the top seal 16 together with the film 4. More specifically, the packaged items 2, which pass through the foreign object detector 15 from the center seal 14 and are sent to the center conveyor 17, are placed on the conveying surface 17b of the center conveyor 17 together with the tubular film 4. The center conveyor 17 conveys the packaged items 2 placed on the conveying surface 17b toward the top seal 16 together with the tubular film 4. In this embodiment, the center conveyor 17 is, for example, a belt conveyor. The center conveyor 17 conveys the packaged items 2 downstream in the conveying direction by moving the conveying surface 17b, which is the outer peripheral surface of the belt 17a, using a drive motor (not shown). The center conveyor 17 is not limited to a belt conveyor, but may be a roller conveyor.

[0027] <Top seal part> Top seal section 16, an example of a second seal section, is located downstream of center seal section 14 in the conveying direction and spaced apart from center seal section 14. More specifically, top seal section 16 is located spaced apart from center seal section 14 so that center conveyor 17 can be placed between top seal section 16 and center seal section 14. As a result, film 4 sealed by center seal section 14 is conveyed to top seal section 16 by center conveyor 17 together with the packaged article 2, as described above. Top seal section 16 is also located upstream in the conveying direction of discharge conveyor 18, which will be described in detail later. More specifically, top seal section 16 is located so as to span between the downstream portion of center conveyor 17 in the conveying direction and the upstream portion of discharge conveyor 18 in the conveying direction (see FIG. 2).

[0028] As shown in FIG. 1 , the top seal unit 16 seals the sealable portions 4c between adjacent packaged items 2 in the tubular film 4. More specifically, multiple packaged items 2 are arranged at intervals in the conveyance direction within the tubular film 4. The top seal unit 16 seals the sealable portions 4c located on the upstream and downstream sides of each packaged item 2 being sequentially conveyed in the conveyance direction. More specifically, the top seal unit 16 seals the sealable portions 4c as the packaged items 2 are transferred from the center conveyor 17 to the discharge conveyor 18. Furthermore, when sealing, the top seal unit 16 cuts the tubular film 4 to divide the sealable portions 4c into the upstream and downstream sides in the conveyance direction. This forms pillow bags 3 made of the film 4 that individually package and seal the packaged items 2. In other words, packages 5 are produced in which the packaged items 2 are individually packaged in the pillow bags 3.

[0029] More specifically, the top seal unit 16 is, for example, a box-motion type sealing mechanism and includes an upper sealer 36, a lower sealer 37, and a drive mechanism 38. The top seal unit 16 may be a rotary type sealing mechanism or another type of sealing mechanism. The upper sealer 36 and the lower sealer 37 are arranged spaced apart in the vertical direction, sandwiching the two conveyors 17, 18. More specifically, the upper sealer 36 is located above the conveying surfaces 17b of the two conveyors 17, and the lower sealer 37 is located below the conveying surfaces 17b. The upper sealer 36 and the lower sealer 37 are configured to be able to move up and down in the vertical direction so as to move toward and away from each other.

[0030] More specifically, the upper sealer 36 and the lower sealer 37 revolve counterclockwise and clockwise in synchronization with each other (i.e., perform a box motion). The upper sealer 36 and the lower sealer 37 approach each other in the gap between the conveyors 17 and 18. The upper sealer 36 and the lower sealer 37 repeatedly move away from and contact each other as they revolve. Each of the upper sealer 36 and the lower sealer 37 incorporates a heater (not shown) and is heated by the heater. Therefore, the upper sealer 36 and the lower sealer 37 approach each other and sandwich the film 4 between them, thereby sealing the sealed portion 4c of the film 4. The spacing of the sealed portion 4c can be adjusted by controlling the revolution speed of each of the upper sealer 36 and the lower sealer 37. After being sealed, the cylindrical film 4 and the packaged items 2 pass between the upper sealer 36 and the lower sealer 37 as they move apart, thereby transferring the cylindrical film 4 and the packaged items 2 from the center conveyor 17 to the discharge conveyor 18.

[0031] The upper sealer 36 is also provided with a cutting blade (not shown). When sealing, the blade cuts the sealed portion 4c of the film 4 so as to separate an upstream portion and a downstream portion in the conveyance direction, thereby producing the package 5. The cutting blade may be provided on the lower sealer 37, or may be provided separately from the upper sealer 36 and the lower sealer 37.

[0032] The drive mechanism 38 drives the upper sealer 36 and the lower sealer 37 to move up and down. In this embodiment, the drive mechanism 38 includes, for example, an electric motor (not shown). The drive mechanism 38 drives the upper sealer 36 and the lower sealer 37 to revolve using the electric motor. This allows the upper sealer 36 and the lower sealer 37 to move closer to and away from each other. Furthermore, by bringing the sealers closer together, the cylindrical film 4 is sealed as described above, and by moving them apart, the packaged items 2 can pass between the two sealers 36, 37.

[0033] <Transport conveyor> The discharge conveyor 18, an example of a second conveyor, conveys packages 5 downstream in the conveying direction, each consisting of a film 4 sealed by the top seal unit 16 and packaged items 2 wrapped in the film. More specifically, the discharge conveyor 18 is positioned downstream in the conveying direction of the center conveyor 17, with a gap between them. The gap is smaller than the outer dimensions of the packaged items 2 and larger than the upper sealer 36 and the lower sealer 37. Therefore, the discharge conveyor 18 receives the packaged items 2 and the tubular film 4 conveyed by the center conveyor 17 on its conveying surface 18b and sends them downstream in the conveying direction. By sending them, the discharge conveyor 18 can seal the sealed portion 4c of the film 4 downstream of the packaged items 2 in the conveying direction with the top seal unit 16. The discharge conveyor 18 then conveys the sealed packages 5 downstream in the conveying direction. In this embodiment, the discharge conveyor 18 is, for example, a belt conveyor. The discharge conveyor 18 rotates the belt 18a using a drive motor (not shown), thereby moving the outer peripheral surface, that is, the conveying surface 18b. This allows the discharge conveyor 18 to send the packaged items 2 and packages 5 wrapped in the film 4 downstream in the conveying direction of the top seal section 16. Note that the discharge conveyor 18 is not limited to a belt conveyor, and may be a roller conveyor.

[0034] <Control device> The control device 19 controls the operation of the various components 11, 12, 14, 16 to 18. As a result, the control device 19 packages the sequentially supplied packaged items 2 with the film 4, as will be described later, to produce packages 5. The control device 19 also acquires the detection results of the foreign object detector 15. The control device 19 stops the movement of the top seal unit 16 based on the acquired detection results. As a result, continuous packages 6 are produced in which some of the sealed portions 4c are not sealed and are not cut.

[0035] <About the operation of the packaging device> The packaging device 1 operates as follows to produce the packaged item 5. The operation of the packaging device 1 will be explained below along the flow of the packaged item 2. The components 11, 12, 14, 16 to 18 of the packaging device 1 are controlled primarily by a control device 19. The control device 19 controls the operating speed of each of the components 11, 12, 14, 16 to 18 in accordance with the conveying speed of the film 4 and the packaged item 2.

[0036] In the packaging apparatus 1, the control device 19 controls the operation of the film supply device 11 to supply the film 4 to the bag former 13 as shown in Figure 1. More specifically, the control device 19 drives the feed roller 22 to unwind the film 4 from the film roll 21 and send it to the bag former 13. The control device 19 also controls the operation of the packaged item supply device 12 to sequentially supply the plurality of packaged items 2 to the bag former 13.

[0037] In the bag former 13, the film 4 supplied from the film supply machine 11 passes through the bag former 13 and is made into a cylindrical bag. At this time, the film 4 is made into a cylindrical bag with both widthwise edge portions 4a hanging downward in the bag former 13. In addition, the packaged items 2 sequentially sent by the packaged item supply machine 12 are fed into the cylindrical film 4, and the bag former 13 rolls up the film 4 so as to wrap the packaged items 2 and make a cylindrical bag.

[0038] The center seal unit 14 pulls in both widthwise edge portions 4a of the film 4, thereby pulling in the tubular film 4 made into bags by the bag former 13. More specifically, in the center seal unit 14, a hanging portion 4b of the film 4 is clamped by a pair of rollers 26a, 27a of each press roller mechanism 26, 27. The control device 19 rotates the pair of rollers 26a, 27a to send the hanging portion 4b downstream in the conveyance direction. This causes the film 4 to be pulled from the bag former 13 into the center seal unit 14.

[0039] The pair of rollers 26a, 27a are heated by a heater (not shown). Therefore, the pair of rollers 26a, 27a clamp the hanging portion 4b of the film 4 while applying pressure, thereby welding both widthwise edge portions 4a to each other. By welding both widthwise edge portions 4a to each other in this manner, the film 4 is formed with a center seal 4d. The film 4 is sent by the rollers 26a, 27a toward the conveying path 31 of the foreign object detector 15. The film 4 is then placed on the conveying path 31 with the center seal 4d folded to one side in the width direction along the way.

[0040] In the foreign object detector 15, the tubular film 4 flows downstream in the conveying direction along the conveying path 31 together with the packaged items 2. As they do so, the tubular film 4 and packaged items 2 pass between a pair of magnetic bias sensors 32, 33. The foreign object detector 15 turns on its detection function at a predetermined timing when the packaged items 2 begin to pass between the pair of magnetic bias sensors 32, 33, and turns off the detection function when the packaged items 2 pass. In this way, the foreign object detector 15 detects the presence or absence of a foreign object within the tubular film 4. More specifically, the pair of magnetic bias sensors 32, 33 amplify the magnetism of the passing objects (i.e., the film 4, the packaged items 2, and the foreign object) during detection. In the case of a film 4 and packaged items 2 made of non-magnetic materials, even if the magnetism is amplified, the change in the magnetic field lines between the magnetic bias sensors 32, 33 is small. Therefore, even when the film 4 and packaged items 2 pass between the pair of magnetic bias sensors 32, 33, they are not detected as foreign objects. On the other hand, when a foreign object made of a magnetic material (e.g., iron, stainless steel, etc.) passes through the pair of magnetic bias sensors 32, 33, the magnetism of the foreign object is amplified, causing a large change in the magnetic field lines between the magnetic bias sensors 32, 33. By detecting this change in the magnetic field lines, the magnetic bias sensors 32, 33 detect that a foreign object has passed between the magnetic bias sensors 32, 33 (i.e., that a foreign object is present). The detection result thus detected is output from the foreign object detector 15 to the control device 19. After the packaged item 2 wrapped in the tubular film 4 passes through the pair of magnetic bias sensors 32, 33, the foreign object detector 15 turns off its detection function. Thereafter, the packaged item 2 wrapped in the tubular film 4 flows along the conveying path 31 toward the center conveyor 17 and is eventually placed on the conveying surface 17b of the center conveyor 17.

[0041] The center conveyor 17 sends the packaged items 2 placed on the conveying surface 17b together with the tubular film 4 toward the top seal section 16. To explain in more detail, the control device 19 drives the belt 17a using a drive motor (not shown) of the center conveyor 17. As a result, the packaged items 2 placed on the conveying surface 17b are sent together with the tubular film 4 to the top seal section 16.

[0042] The sealed portion 4c of the tubular film 4 between adjacent packaged items 2 is fed to the top seal unit 16 at the predetermined timing described above. The top seal unit 16 seals and then cuts the fed sealed portion 4c. That is, the top seal unit 16 forms a top seal 4e between the adjacent packaged items 2 and then cuts it. More specifically, the control device 19 controls the movement of the drive mechanism 38 of the top seal unit 16 to bring the upper sealer 36 and lower sealer 37 close to each other at the predetermined timing. As a result, the sealed portion 4c is sealed and cut by the upper sealer 36 and lower sealer 37.

[0043] More specifically, while continuing to operate the two conveyors 17, 18, the control device 19 operates the top seal unit 16 in the following manner in accordance with the detection result of the foreign object detector 15. That is, when the control device 19 acquires the detection result of the foreign object detector 15, it executes the drive determination process shown in the flowchart in FIG. 3. Once the drive determination process is executed, the process proceeds to step S1. In step S1, which is the determination step, the control device 19 determines whether or not a foreign object is present based on the detection result of the foreign object detector 15. If it is determined that no foreign object is present, the process proceeds to step S2. On the other hand, if it is determined that a foreign object is present, the process proceeds to step S3.

[0044] In step S2, which is the drive step, the control device 19 causes the top seal unit 16 to seal and cut the sealable portion 4c on the downstream side of the packaged item 2 in the conveyance direction. More specifically, the control device 19 drives the drive mechanism 38. This brings the upper sealer 36 and the lower sealer 37 closer together, sealing and cutting the sealable portion 4c on the downstream side of the packaged item 2 in the conveyance direction. Once the sealable portion 4c is sealed, the process returns to step S1. The drive determination process is then repeated until the packaging operation by the packaging device 1 is completed. Thereafter, the upper sealer 36 and the lower sealer 37 move apart, causing the tubular film 4 to pass between the sealers 36 and 37. The same drive determination process is then performed on the sealable portion 4c on the upstream side of the conveyance direction, sealing and cutting it, thereby producing a package 5. The formed package 5 is then carried out by the discharge conveyor 18.

[0045] In step S3, which is a drive stopping step, the control device 19 stops the sealing operation of the top seal unit 16 to seal the film 4. More specifically, the control device 19 stops the sealing operation of the top seal unit 16 downstream in the conveyance direction of the detected foreign object. In this embodiment, the control device 19 stops the sealing operation of the top seal unit 16 so that the sealed portion 4c downstream in the conveyance direction of the detected foreign object and immediately adjacent to the foreign object is not sealed or cut. The control device 19 calculates the position of the sealed portion 4c that will not be sealed or cut based on the conveyance speed of the center conveyor 17, and stops the sealing operation of the top seal unit 16 based on the calculated position. Thereafter, when the sealed portion 4c passes through the top seal unit 16 (more specifically, the gap between the conveyors 17 and 18), the control device 19 returns to step S1 to resume the sealing operation of the top seal unit 16. If it is determined again that no foreign matter has been detected, the process proceeds to step S2 and the sealing operation is resumed, sealing the sealed portion 4c further upstream in the conveying direction than the unsealed sealed portion 4c. This forms a package 6 in which adjacent packaged items 2 are placed in a single pillow bag 3 (i.e., a package in which two packaged items 2 are continuously wrapped). The package 6 is then carried out in this state by the carry-out conveyor 18. This makes it easy to distinguish a package 6 containing a foreign matter from other packages 5.

[0046] Furthermore, in the packaging device 1 of this embodiment, the control device 19 receives detection results regarding the presence or absence of foreign objects from the foreign object detector 15. This allows the manufacturing device 19 to detect the presence of foreign objects in the packaging process, which is one step in the manufacturing process from producing a product from raw materials to packaging, wrapping, and shipping. This allows for improved traceability in the manufacturing process.

[0047] In the packaging device 1 of this embodiment configured as described above, the foreign object detector 15 is disposed between the center seal portion 14 and the top seal portion 16, which are spaced apart in the conveyance direction. Conventionally, the two seal portions 14, 16 are spaced apart from each other. Therefore, by disposing the foreign object detector 15 between the center seal portion 14 and the top seal portion 16, the overall length of the packaging device 1 can be prevented from increasing. Furthermore, the film 4 is formed into a cylindrical shape by sealing both widthwise edge portions 4a downstream of the center seal portion 14, making it difficult for foreign objects to enter the film 4. Therefore, by disposing the foreign object detector 15 between the center seal portion 14 and the top seal portion 16, it is possible to prevent foreign objects from entering the film 4 after it has passed through the foreign object detector 15. Therefore, foreign objects in the film 4 can be reliably detected.

[0048] Furthermore, in the packaging device 1 of this embodiment, the foreign object detector 15 is located between the center seal portion 14 and the center conveyor 17 in the conveyance direction. This allows the foreign object detector 15 to be positioned away from the top seal portion 16, which reduces the influence of the top seal portion 16 on the foreign object detector 15 when detecting foreign objects. In this embodiment, it is possible to reduce the influence of metal parts that make up the top seal portion 16 on changes in the magnetic field lines. This allows for more reliable detection of foreign objects.

[0049] Furthermore, in the packaging device 1 of this embodiment, the foreign object detector 15 is a magnetic bias magnetic field metal detector. A magnetic bias magnetic field metal detector can inspect only one gate. Furthermore, a magnetic bias magnetic field metal detector can eliminate the need for a power source to drive the sensor module. This allows the packaging device 1 to be made more compact and foreign objects to be detected more reliably. Furthermore, a foreign object detection function can be installed in the packaging device with a simple configuration, improving maintainability.

[0050] Furthermore, in the packaging device 1 of this embodiment, the foreign object detector 15 has a vibration-damping mechanism 35 that suppresses vibrations transmitted from the seal portions 14, 16. This prevents the foreign object detector 15 from vibrating, allowing the foreign object detector 15 to detect foreign objects more accurately.

[0051] Furthermore, in the packaging device 1 of this embodiment, when the foreign object detector 15 detects a foreign object, the control device 19 stops the operation of the top seal unit 16. This makes it easier to find a package 5 containing a foreign object and prevents the package 5 containing the foreign object from being mixed with other packages 5.

[0052] Furthermore, in the packaging device 1 of this embodiment, when the foreign object detector 15 detects a foreign object, the control device 19 stops the sealing operation of the top seal unit 16 downstream of the detected foreign object in the conveying direction while moving the center conveyor 17 and the discharge conveyor 18. This forms a package 6 containing adjacent packaged items 2. This makes it easy to distinguish a package 6 containing a foreign object from other packages 5.

[0053] Furthermore, in the packaging device 1 of this embodiment, after the foreign object detector 15 detects a foreign object and stops the sealing operation of the top seal unit 16, the control device 19 resumes the sealing operation of the top seal unit 16. This prevents the packaging operation from being stopped every time the foreign object detector 15 detects a foreign object, thereby preventing a decrease in yield.

[0054] <Other embodiments> The packaging device 1 of this embodiment is a normal pillow packaging machine, but it may also be an inverted pillow packaging machine. Furthermore, the packaging device 1 of this embodiment is a horizontal pillow type packaging device, but it may also be a vertical pillow type packaging device. In this case, the conveying direction is vertical. Furthermore, in the packaging device 1 of this embodiment, the first sealing unit may be a side sealing unit that butts and seals both widthwise edge portions 4a of the film 4 on one or the other widthwise side (i.e., seals the side of the packaging bag). Furthermore, in this embodiment, the foreign object detector 15 is disposed between the center seal unit 14 and the center conveyor 17, but it may also be disposed on the center conveyor 17, as long as it is disposed between the center seal unit 14 and the top seal unit 16.

[0055] In the packaging device 1 of this embodiment, the sealed portion 4c that is not sealed or cut is located downstream in the conveyance direction of the foreign object, but it may also be located upstream in the conveyance direction of the foreign object, or on both sides of the conveyance direction. Furthermore, the sealed portion 4c that is not sealed or cut may be located not only immediately adjacent to the foreign object, but also at multiple locations. Furthermore, in the packaging device 1 of this embodiment, when a foreign object is detected, the sealing operation of the top seal unit 16 is temporarily stopped. However, the sealing operation of the top seal unit 16 may also be completely stopped (for example, until the operator restarts the operation). Furthermore, the sealing operation of the top seal unit 16 does not necessarily have to be stopped when a foreign object is detected. In this case, it is preferable to provide an exclusion device that removes packages containing foreign objects from the discharge conveyor 18.

[0056] Furthermore, in the packaging device 1 of this embodiment, a packaged item position detection sensor may be provided between the center seal unit 14 and the foreign object detector 15. The packaged item position detection sensor detects the position of the packaged item 2 to be packaged in the tubular film 4. The control device 19 switches the foreign object detector 15 on and off based on the detected position of the packaged item 2. This allows the foreign object detector 15 to detect foreign objects more reliably. Furthermore, the control device 19 detects whether the packaged item 2 is located in the sealed portion 4c (i.e., whether it is misaligned) based on the detected position of the packaged item 2. If the packaged item 2 is misaligned, the control device 19 stops the movement of the top seal unit 16. This prevents the packaged item 2 from being crushed by the top seal. In this way, in the packaging device 1, the foreign object detector 15 and the top seal unit 16 can share a packaged item position detection sensor. For example, if the foreign object detector 15 is located downstream of the top seal unit 16, the positions of the sealed and cut packages 6 will vary, so a packaged item position detection sensor is required for each foreign object detector 15 and top seal unit 16. As described above, in the packaging device 1, the foreign object detector 15 and the top seal unit 16 can share a packaged item position detection sensor, so the number of parts in the packaging device 1 can be reduced.

[0057] [Additional Notes] The present invention can also be expressed as follows.

[0058] A packaging device in a first aspect is a packaging device that sequentially packages a plurality of packaged items transported from upstream to downstream in a conveying direction, and includes a packaged item supply section that sequentially supplies the packaged items, a bag making section that butts both widthwise edge portions together to form a tubular bag from film so as to wrap each of the packaged items sequentially supplied by the packaged item supply section, a first sealing section that seals both widthwise edge portions of the film that have been butted together in the bag making section, a second sealing section that is located downstream in the conveying direction from the first sealing section and seals sealed portions between adjacent packaged items in the film, and a foreign object detector that detects foreign objects in the film, and the foreign object detector is positioned between the first sealing section and the second sealing section in the conveying direction.

[0059] According to the above aspect, the foreign object detector is disposed between the first sealing unit and the second sealing unit, which are spaced apart in the conveying direction. Therefore, the two sealing units are conventionally spaced apart. Therefore, by disposing the foreign object detector between the first sealing unit and the second sealing unit, it is possible to prevent the overall length of the packaging device from increasing. Furthermore, since the film is tubular with both edges sealed downstream of the first sealing unit, it is difficult for foreign objects to enter the film. Therefore, by disposing the foreign object detector between the first sealing unit and the second sealing unit, it is possible to prevent foreign objects from entering the film after it has passed through the foreign object detector. Therefore, foreign objects in the film can be reliably detected.

[0060] The packaging device in a second aspect is the packaging device of the first aspect, further comprising a first conveyor that is arranged between the first sealing section and the second sealing section and transports the packaged item to be packaged in the film sealed in the first sealing section together with the film to the second sealing section, and the foreign object detector is provided between the first sealing section and the first conveyor in the transport direction.

[0061] According to the above aspect, the foreign object detector is provided between the first seal portion and the first conveyor in the conveying direction. Therefore, the foreign object detector can be positioned away from the second seal portion, which reduces the influence of the second seal portion on the foreign object detector when detecting a foreign object. This allows for more reliable detection of foreign objects.

[0062] A packaging device according to a third aspect is the packaging device according to the second or third aspect, wherein the foreign object detector is a magnetic bias type magnetic field line type metal detector.

[0063] According to the above aspects, a magnetic bias type magnetic field line metal detector can inspect only one gate. Furthermore, a magnetic bias type magnetic field line metal detector can eliminate the need for a power source for the sensor module. This allows the packaging device to be more compact and more reliably detect metal foreign objects. Furthermore, a foreign object detection function can be installed in the packaging device with a simple configuration, improving maintainability.

[0064] In a fourth aspect, in the packaging device of any one of the first to third aspects, the foreign object detector has a vibration isolation mechanism that suppresses vibrations transmitted from each seal portion.

[0065] According to the above aspect, the foreign object detector has a vibration-damping mechanism that suppresses vibrations transmitted from each seal portion. This prevents the foreign object detector from vibrating, allowing the foreign object detector to detect foreign objects more accurately.

[0066] In a fifth aspect, the packaging device is the packaging device of any one of the first to fourth aspects, further comprising a control device that controls the sealing operation of the second sealing unit to seal the film, and the control device stops the sealing operation of the second sealing unit when the foreign object detector detects a foreign object.

[0067] According to the above aspect, when the foreign object detector detects a foreign object, the control device stops the operation of the second sealing unit, which makes it easier to find a packaging bag containing a foreign object and prevents the foreign object from being mixed in with other packages.

[0068] A packaging device in a sixth aspect is the packaging device of the fifth aspect, further comprising a first conveyor that transports the packaged item to be packaged in the film sealed by the first sealing section together with the film to the second sealing section, and a second conveyor that transports the packaged item packaged in the film sealed by the second sealing section downstream of the second sealing section, and when the foreign object detector detects a foreign object, the control device continues to move the first conveyor and the second conveyor while stopping the sealing operation of the second sealing section at least on the upstream side and downstream side of the transport direction of the detected foreign object.

[0069] According to the above aspect, when the foreign object detector detects a foreign object, the control device stops the sealing operation of the second seal unit on at least one of the upstream and downstream sides of the detected foreign object in the conveying direction while moving the first conveyor and the second conveyor. This forms a package containing the adjacent packaged item. Therefore, it is easy to distinguish a package containing a foreign object from other packages.

[0070] In a seventh aspect, the packaging device is the packaging device of the sixth aspect, wherein the control device resumes the sealing operation of the second sealing unit after the foreign object detector detects a foreign object and stops the sealing operation of the second sealing unit.

[0071] According to the above aspect, the control device restarts the sealing operation of the second seal unit after the foreign object detector detects a foreign object and stops the sealing operation of the second seal unit, thereby preventing a decrease in yield due to a packaging operation being stopped every time the foreign object detector detects a foreign object.

[0072] From the above description, many improvements and other embodiments of the present disclosure will be apparent to those skilled in the art. Therefore, the above description should be construed as illustrative only and is provided for the purpose of teaching those skilled in the art the best mode for carrying out the present disclosure. Details of the structure and / or function thereof can be substantially changed without departing from the spirit of the present disclosure. [Explanation of symbols]

[0073] 1 Packaging equipment 2 Items to be packaged 4 Film 4a Both edges in the width direction 4c Sealed part 12 Packaged material supply machine (packaged material supply section) 13 Bag making machine (bag making department) 14 Center seal part (first seal part) 15 Foreign object detector 16 Top seal part (second seal part) 17 Center conveyor (first conveyor) 18. Discharge conveyor (second conveyor) 19 Control device 35 Anti-vibration mechanism

Claims

1. A packaging device that sequentially packages a plurality of items to be packaged that are conveyed from the upstream side to the downstream side in a conveying direction, A packaged item supply section that sequentially supplies the packaged items; a bag making section that butts both widthwise edge portions of the film together to form a tubular bag so as to wrap each of the articles to be packaged that are sequentially supplied by the article supply section; a first sealing section that seals both widthwise edge portions of the film that have been butted together in the bag making section; A second sealing section is provided downstream of the first sealing section in the conveying direction and separates therefrom, and seals the sealed portions between the adjacent packaged articles relative to the film; a magnetic bias type magnetic field line type metal detector having a detection function for detecting foreign objects in the film; a first conveyor disposed between the first sealing section and the second sealing section, which conveys the packaged item to be packaged in the film sealed at the first sealing section together with the film to the second sealing section; The foreign object detector has a vibration-damping mechanism that suppresses vibrations transmitted from each sealing unit, and is positioned between the first sealing unit and the first conveyor in the conveying direction so that it is closer to the first sealing unit than to the second sealing unit, and the packaging device turns on its detection function when the packaged item begins to pass through the foreign object detector and turns off the detection function when the packaged item has passed the foreign object detector.

2. The device further includes a control device that controls a sealing operation of the second sealing unit to seal the film, The packaging device according to claim 1 , wherein the control device stops the sealing operation of the second sealing unit when the foreign object detector detects a foreign object.

3. The device further includes a second conveyor that transports the packaged item packaged in the film sealed by the second sealing section to the downstream side of the second sealing section, 3. The packaging device of claim 2, wherein when the foreign object detector detects a foreign object, the control device continues to move the first conveyor and the second conveyor while stopping the sealing operation of the second seal section on at least one of the upstream and downstream sides of the detected foreign object in the conveying direction.

4. The packaging device according to claim 3 , wherein the control device restarts the sealing operation of the second sealing unit after the foreign object detector detects a foreign object and stops the sealing operation of the second sealing unit.

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