Container folding device and container folding method

Abstract

To provide a container folding device which can fold different types of folding containers with one container folding device, and to provide a container folding method capable of folding different types of folding containers.SOLUTION: A container folding device 100 folds a middle folding container M and a four-folding container F and includes container discrimination means 20 for discriminating the middle folding container M from the four-folding container F.SELECTED DRAWING: Figure 2

Description

[Technical Field]

[0001] The present invention relates to a container folding device and a container folding method, and more particularly to a container folding device and a container folding method for folding center-fold containers and four-fold containers. [Background technology]

[0002] For example, parts used in assembly work in a factory are usually housed in containers for delivery and storage. Because containers for housing these parts take up space when not in use, foldable containers are widely used so that they can be folded and stored when not in use.

[0003] In workplaces where many parts are used, such as automobile assembly, a huge number of containers are used, so folding up the containers after use by hand would be a huge task.

[0004] To address this issue, a container folding device such as that described in Patent Document 1 is known. The container to be folded by the container folding device of Patent Document 1 is a container that has a locking mechanism that maintains the connected state of the side panels (walls), and this folding device is designed for so-called four-fold containers.

[0005] Meanwhile, there are various types of foldable containers, and a container folding device such as that described in Patent Document 2 is also known. The container to be folded by the container folding device of Patent Document 2 is a container having foldable opposing walls, and this folding device is for so-called center-foldable containers. [Prior art documents] [Patent documents]

[0006] [Patent Document 1] Japanese Patent Application Publication No. 2023-139373 [Patent Document 2] Patent No. 6168289 Summary of the Invention [Problem to be solved by the invention]

[0007] The container folding devices of Patent Documents 1 and 2 are dedicated container folding devices for each type of container, such as for four-fold containers or for center-folded containers.

[0008] However, in reality, four-fold containers and center-foldable containers are often used together at the site. In this situation, if a folding device is used to fold containers, it will be necessary to prepare two separate devices, one disclosed in Patent Document 1 and the other disclosed in Patent Document 2, or one container will be folded by the device and the other will be folded by hand.

[0009] Therefore, an object of the present invention is to provide a container folding device that can fold different types of folding containers with a single container folding device, and to provide a container folding method that can fold different types of folding containers. [Means for solving the problem]

[0010] In order to solve the above-mentioned problems, one aspect of the present invention provides a container-folding device that folds a four-fold container having a square bottom plate provided at a lower part, opposing first and second side plates each having one end rotatably attached to the bottom plate, opposing third and fourth side plates each having one end rotatably attached to the bottom plate, and first and second locking mechanisms provided at the upper parts of the first and second side plates, respectively, for locking the connection of the third side plate to the fourth side plate, and a center-folding container having a square bottom plate provided at a lower part, a square frame provided at an upper part and having an opening formed therein, opposing first and second side plates each having one end rotatably attached to the frame, and third and fourth side plates provided opposite so as to be adjacent to the first and second side plates and which are foldable, and is characterized by comprising a container discrimination means that distinguishes between the four-fold container and the center-folding container.

[0011] With this configuration, the device has a container discrimination means, which allows it to determine whether the container to be folded is a four-fold container or a center-fold container. Therefore, by performing folding operations according to the type of container, a single device can accommodate different types of folding. When accommodating different types of folding, in addition to a method of folding with different operations at a single folding position, as in the folding unit 15 of the embodiment described below, another method is to provide folding positions corresponding to each container.

[0012] Furthermore, the container folding device of the present invention is provided with a folding unit including a first pressing portion that presses the first side plate inward, a second pressing portion that presses the second side plate inward, a third pressing portion that presses the third side plate inward, a fourth pressing portion that presses the fourth side plate inward, and a lock pressing portion that presses the lock mechanisms provided on the first and second side plates, and it is preferable that the container discrimination means discriminates based on the pressing action of the lock pressing portion.

[0013] With this configuration, it is possible to use the lock pressing unit that releases the lock required to fold a four-fold container, and if the lock can be pressed, it is known that the container to be folded is a four-fold container, so the operation to fold the four-fold container can be performed, and if the lock cannot be pressed, it is known that the container to be folded is a center-foldable container, so the operation to fold the center-foldable container can be performed. Also, since a single folding unit 15 as in the embodiment can be used to fold different containers, the device can be made more compact.

[0014] In addition, in the container folding device of the present invention, it is preferable that the lock pressing portion is made of a rod-shaped pressing protrusion located above the lock mechanism, and that the tip side of the pressing protrusion is tiltable inward.

[0015] With this configuration, when folding a four-fold container, the pressing protrusions do not hinder the first and second side panels from moving inward, thereby reducing the number of folding failures of the container caused by the folding operation.

[0016] In addition, in the container folding device of the present invention, it is preferable that the folding unit further includes a container conveying section, and that the first to fourth pressing sections each include an arm that swings up and down, with a roller attached to the tip of the arm. With this configuration, when a container is being transported, the arm can be retracted upward or downward, thereby preventing the transport of the container from being hindered.

[0017] Furthermore, in the container folding device of the present invention, it is preferable that a stacking and discharging unit that stacks and transports folded containers is further provided downstream of the folding unit, and that the stacking of the folded containers is carried out by moving the folded containers upward and stacking them from below the previously folded container. When stacking containers by moving them downwards as in Patent Document 2, a large space is required below the device to stack them high, but with a configuration in which containers are stacked by moving them upwards as in the present invention, the space above the device can be utilized.

[0018] In the container folding device of the present invention, it is preferable that the folding unit further includes a defective product discriminating means for discriminating defective folded products. Folding defects of a container can occur due to deformation of the side plates of the container or parts remaining on the bottom plate, but the defective product discriminating means can remove any folded defective products at an early stage.

[0019] As a specific example of the defective product determination means, for example, if the pressing action of the first to fourth pressing parts stops midway, it can be determined that the side panels are not folded properly and that the product is defectively folded. Also, for example, an optical sensor consisting of a light-emitting part and a light-receiving part can be used to determine that the container is defectively folded if it is detected at a position higher than a predetermined position after the folding operation. Furthermore, in the configuration of the stacked discharge unit described above, defective containers can be preferentially discharged by passing them under stacked containers.

[0020] In addition, it is preferable that the container folding device of the present invention further comprises a stacking separation unit upstream of the folding unit for separating and transporting stacked containers. This configuration eliminates the need to take the trouble of separating the containers one by one before folding, thereby improving work efficiency.

[0021] In order to solve the above-mentioned problems, a container folding method according to one embodiment of the present invention provides a method for folding a container, comprising: a four-fold container having a square bottom plate provided at a lower portion, opposing first and second side plates each having one end rotatably attached to the bottom plate, opposing third and fourth side plates each having one end rotatably attached to the bottom plate, and a locking mechanism provided at an upper portion of each of the first and second side plates for locking the connection state of the third side plate and the fourth side plate; and a center-foldable container having a square bottom plate provided at a lower portion, a square frame provided at an upper portion and having an opening formed therein, opposing first and second side plates each having one end rotatably attached to the frame, and third and fourth side plates each being provided adjacent to the first and second side plates and being foldable, a first pressing section that presses the first side plate inward, a second pressing section that presses the second side plate inward, a third pressing section that presses the third side plate inward, a fourth pressing section that presses the fourth side plate inward, and a lock pressing section that presses the lock mechanisms provided on the first and second side plates, wherein if the lock pressing section is able to press the lock, it determines that the container to be folded is the four-fold container, and if the lock pressing section is not able to press the lock, it determines that the container to be folded is the center-fold container, and based on the result of distinguishing between the four-fold container and the center-fold container, the first to fourth pressing sections are operated to fold the container.

[0022] The container folding method of the present invention can fold different types of folding containers. For example, if a four-fold container is determined to be a four-fold container, the first and second pressing units are operated, and then the third and fourth pressing units are operated to fold the container. In other words, a four-fold container can be folded efficiently by folding the first and second side panels, and then folding the third and fourth side panels.

[0023] Furthermore, if the container is determined to be a center-foldable container, the first and second pressing units are maintained in an operating state, then either the third or fourth pressing unit is operated, after which the operation of the first and second pressing units is terminated, and the last remaining third or fourth pressing unit is operated to fold the container. In other words, if the container is a center-foldable container, the first and second pressing units are operated to maintain the folded state of the first and second side panels, then either the third or fourth pressing unit is operated to first fold either the third or fourth side panel, then the operation of the first and second pressing units is terminated, and the last remaining third or fourth pressing unit is operated, thereby preventing poor folding due to interference between the folding operations that can occur when the third and fourth side panels are folded simultaneously, and enabling efficient folding. [Brief explanation of the drawings]

[0024] [Figure 1] 10A to 10C are images showing the folding procedure of a center-foldable container and the folding procedure of a four-fold container folded by a container folding device according to an embodiment of the present invention. [Figure 2] 1 is a front view showing a schematic overall configuration of a container folding device according to an embodiment. [Figure 3] 5A and 5B are schematic diagrams illustrating a separation method of the stacking separation unit according to the embodiment. [Figure 4] 10 is an image showing a separation method of the stacking separation unit. [Figure 5] FIG. 1 is a schematic diagram showing a method for folding a four-fold container. [Figure 6] FIG. 1 is a schematic diagram showing a method for folding a four-fold container. [Figure 7] This is an image showing how to fold a four-fold container. [Figure 8] 1 is a schematic diagram showing a folding method for a center-foldable container. FIG. [Figure 9] 1 is a schematic diagram showing a folding method for a center-foldable container. FIG. [Figure 10] This is an image showing how to fold a center-foldable container. [Figure 11]10 is a schematic diagram showing a stacking method of the stacking discharge unit. FIG. [Figure 12] 10 is an image showing a stacking method of the stacking discharge unit. [Figure 13] 10A and 10B are schematic diagrams illustrating a discharging method of the stacking discharging unit. [Figure 14] 10 is an image showing a fault detection. DETAILED DESCRIPTION OF THE INVENTION

[0025] Hereinafter, a mode for carrying out the present invention will be described with reference to the embodiments and drawings, but the embodiments shown below are not intended to limit the present invention to those described herein, and the present invention is equally applicable to various modifications without departing from the technical idea set forth in the claims. Note that in each drawing used for explanation in this specification, each component is shown at a different scale so that each component is large enough to be recognizable on the drawing, and is not necessarily shown in proportion to its actual size.

[0026] [Embodiment] The container folding device according to the embodiment of the present application is a container folding device 100 (hereinafter simply referred to as the folding device 100 as appropriate) that folds a mixture of four-fold containers F and center-foldable containers M.

[0027] [4-fold container] First, a general manual folding method for a commercially available four-fold container F will be described using A1 to A4 in FIG. 1, this so-called four-fold container F includes a rectangular bottom plate F1 provided at the bottom, first and second side plates F2 and F3 facing each other and rotatably attached to the bottom plate F1, third and fourth side plates F4 and F5 facing each other and rotatably attached to the bottom plate F1, and first and second locking mechanisms F6 and F7 provided at the tops of the first and second side plates F2 and F3, respectively, for locking the connection between the third side plate F4 and the fourth side plate F5. As shown in A2 of FIG. 1, the connection is unlocked by pressing down first and second locking buttons F8 and F9 of the first and second locking mechanisms F6 and F7.

[0028] This four-fold container F can be folded downward with the first and second side panels F2 and F3 facing inward as shown in A2 of Fig. 1 by first depressing the lock buttons F8 and F9 to release the lock. Then, as shown in A3 of Fig. 1, the third and fourth side panels F4 and F5 are folded downward with the third and fourth side panels F4 and F5 facing inward. In this way, the folding of the container F is completed as shown in A4 of Fig. 1.

[0029] [Bent container] Next, a general manual folding method for a commercially available center-foldable container M will be described with reference to B1 to B4 in FIG. As shown in Figure 1, this so-called center-foldable container M comprises a rectangular bottom plate M1 provided at the bottom, a rectangular frame body M2 provided at the top and having an opening formed therein, opposing first and second side plates M3 and M4 each of which has one end rotatably attached to the frame body M2, and third and fourth side plates M5 and M6 which are adjacent to and opposite the first and second side plates M3 and M4 and can be folded.

[0030] In this type of center-foldable container F, first, the first and second side panels M3 and M4 are folded upward toward the inside of the frame M2, as shown in B2 of Fig. 1. Then, while maintaining this state, the third side panel M5 is folded as shown in B3 of Fig. 1. The reason why the first and second side panels M3 and M4 are kept folded upward is because, if they were not, their own weight would cause them to return to their original positions, making it impossible to fold the third side panel M5. The third side panel M5 is folded by the pivotally connected upper and lower panels M7 and M8 bending inward.

[0031] Then, as shown in B3 of Fig. 1, the fourth side plate M6 is similarly folded after the previously folded third side plate M5. Note that the folding of the fourth side plate M6 is also achieved by folding the rotatably connected upper and lower side plates M9 and M10 inward, as shown in Fig. 8 and other drawings, which will be described later. In this way, the folding of the container M is completed as shown in B4 of Fig. 1.

[0032] [Unit configuration] The overall configuration of the folding device 100 will be described with reference to FIG. The folding device 100 includes a stacking / separating unit 1, a folding unit 2, a stacking / discharging unit 3, and a control unit 4. The stacking separation unit 1 separates the stacked containers F, M one by one, and is composed of a stacking separation supply section 11, a separation section 12, and a first conveyor belt 13. The folding unit 2 folds the containers that have flowed from the stacking / separation unit 1 located upstream, and is composed of a folding supply section 14, a folding section 15, and a second conveyor belt 16. The stacking and discharging unit 3 stacks an arbitrary number of folded containers flowing from the folding unit 2 located upstream, and discharges them in a stacked state, and is composed of a stacking section 17, a discharging section 18, and a third conveyor belt 19. The first to third conveyor belts 13, 16, 19 are used to convey the containers F and M, and in this embodiment are two belt conveyors located at both ends of the container.

[0033] The control unit 4 controls, based on a program, the overall operation of the folding device 100. The control unit 4, together with various sensors and the like, constitutes a container discrimination means 20 and a defective product discrimination means 21, which will be described later.

[0034] In this way, the folding device 100 is made up of three units. Therefore, for example, when the installation area for the device is limited, it is easy to select the units to be used, for example, to configure the device so that only the folding unit 2 is used.

[0035] Next, the main configuration of the folding device 100 will be described in more detail. [Stacking separation unit] When folding, the folding device 100 does not require the user to set each container one by one, but can set stacked containers, in which four-fold containers F and center-folded containers M are mixed and stacked, in the stacking separation supply section 11. Therefore, when folding containers, the user only needs to set the stacked containers in the stacking separation supply section 11, eliminating the need for the user to perform separation work, making the folding device 100 highly efficient. The stacked containers placed on the first conveyor belt 13 are then automatically separated into individual containers in the next separating section 12.

[0036] [Separation section] The main parts of the separation section 12 of the stacking separation unit 1 will be described using C1 to C9 (drawings) in Fig. 3 and D1 to D6 (images) in Fig. 4. The viewing direction is the flow direction of the containers F and M. C1 in Fig. 3 is a cross-sectional view showing the state in which the containers F and M have been transported to the separation section 12 by the first conveyor belt 13 before being stacked and separated.

[0037] In this C1, the first and second, fourth and fifth stacked containers from the bottom are four-fold containers F, and the third stacked container from the bottom is a center-fold container M. In this way, the stacked containers are a mixture of four-fold containers F and center-fold containers M.

[0038] As shown in C1, first and second recesses F10, F11 are formed on the outside of the first and second side panels F2, F3 of the four-fold container F. These recesses allow the user to hook their fingers into the first and second recesses F10, F11, making it easier to carry the container. Similar to the recesses provided on normal containers, the center-foldable container M also has first and second recesses M11, M12. The separating section 12 includes a separating lift 31 located between two belt conveyors that are the first transport belt 13, and a pair of first and second separating plates 32, 33. The separation lift 31 raises and lowers the containers F and M and is movable up and down.

[0039] The first and second separator plates 32, 33 are pivotally supported so as to be able to open and close by opening and closing operations upward from the horizontal, as shown at C2 and C5. When the separator plates 32, 33 are in the upwardly opened state as shown at C2, the stacked containers can pass up and down between the separator plates 32, 33.

[0040] On the other hand, when the separation plates 32, 33 are closed and horizontal as in C4, they are caught in the first and second recesses F10, F11, M11, M12 of the containers F, M, like a user's hands, allowing the containers to be held. The separation operation in the separator 12 will now be described.

[0041] From the state C1, the stacked containers are lifted by the separation lift 31, and the open separation plates 32, 33 are positioned at the first and second recesses F10, F11 of the first tier of four-fold container F (C2). Then, when the separation plates 32, 33 close (C3) and the four-fold container F is lowered by the separation lift 31, the separation plates 32, 33 engage with the recesses F10, F11 to hold the four-fold container F (C4, D1). In this way, the stacked containers F, M are ready to be separated one tier at a time by repeating the steps C5 to C9.

[0042] From the state C4, the separation lift 31 rises (D2), the first tier of four-fold containers F is lifted slightly, and the separation plates 32, 33 can be opened (C5, D3). Then, with the separation plates 32, 33 in the open state (C6, D4), the separation lift 31 is lowered to lower the stacked containers so that the separation plates 32, 33 are positioned at the recesses F10, F11 of the second tier of four-fold containers F (C7).

[0043] Then, the separator plates 32, 33 close (C8, D5), and the separation lift 31 is further lowered, thereby lowering the first tier of four-fold containers F to the first conveyor belt 13 (C9, D6). At this time, the recesses F10, F11 of the second tier of four-fold containers F engage with the separator plates 32, 33, so that the second tier of four-fold containers F are supported by the separator plates 32, 33. Therefore, the first tier of four-fold containers F is separated from the stacked containers and placed on the first conveyor belt 13.

[0044] After C8, the containers F and M on the first conveyor belt 13 are transported to the next folding unit 2 and disappear from the separation section 12, resulting in the state of C4. Therefore, by repeating C4 to C9 thereafter, the stacked containers F and M are separated one layer at a time.

[0045] [Folding unit] When folding a container, the folding device 100 uses a container discrimination means 20 to determine whether the container to be folded is a four-fold container F or a center-foldable container M, and performs a folding operation corresponding to each of the identified containers. Then, the folding and supplying section 16 receives the container sent from the stacking and separating unit 1 located upstream and supplies it to the next folding section 15.

[0046] [Folding section] The main parts of the folding section 15 of the folding unit 2 will be described using E1 to E6 in Figures 5 and 6 and G1 to G8 in Figures 8 and 9. Figures E1 to E6 and G1 to G8 are views from different viewing directions. The figures (E1 to E4, G1 to G3, G6) in which two second conveyor belts 16 are shown on the left and right are partial cross-sectional views showing the cross sections of the first and second side plates F2, F3, M3, and M4. The figures (E5, E6, G4, G5, G7, G8) in which one second conveyor belt 16 is shown in the center are partial cross-sectional views showing the cross sections of the third and fourth side plates F4, F5, M5, and M6.

[0047] As shown in E1 to E6 in Figures 5 and 6, the folding section 15 consists of a folding lift 41 located between two belt conveyors that are the second conveyor belt 16, first and second lock pressing sections 42 and 43, and first to fourth pressing sections 44 to 47. The folding lift 41 is movable up and down, and raises and lowers the containers F, M from the second conveyor belt 16 to the folding position.

[0048] 5, the first and second lock pressing portions 42, 43 include rod-shaped first and second pressing protrusions 53, 54 that are moved in and out by first and second cylinders 51, 52. These cylinders 51, 52 may be hydraulic cylinders or electric DC solenoids (plungers).

[0049] As shown in E1 of Fig. 5, the pressing protrusions 53, 54 are disposed in positions that press down the lock buttons F8, F9 of the four-fold container F. When the first and second side plates F2, F3 of the four-fold container F are folded inward with the pressing protrusions 53, 54 extended, the lock pressing portions 42, 43 are pivotally supported and rotate to move inward so that the tip ends of the pressing protrusions 53, 54 tilt inward as shown in E3 of Fig. 5. The rotation of the lock pressing portions 42, 43 is returned to their original positions by the first and second coil springs 55, 56.

[0050] The first to fourth pressing portions 44 to 47 press the first to fourth side plates F2 to F5 of the four-fold container F and the first to fourth side plates M3 to M6 of the center-foldable container M inward, and are located on the left and right sides and the front and back of the container.

[0051] More specifically, the first to fourth pressing sections 44 to 47 include first to fourth arms 65 to 68 that perform link movement. The first to fourth arms 65 to 68 are rotatably supported by first to fourth fulcrum shafts 69 to 72, respectively, and are configured such that first to fourth force point shafts 73 to 76, which serve as force points, are bent and extended by first to fourth cylinders 77 to 80, respectively. First to fourth rollers 61 to 64 that actually press the side plates of the container are rotatably attached to the points of application of the first to fourth arms 65 to 68.

[0052] The first to fourth rollers 61 to 64 that press against the side plates of the container may not have such a rotatable roller structure, but may instead have a simple rod-shaped protrusion structure. However, since the side plates of the containers F and M usually have uneven surfaces such as recesses F10, F11, M11, and M12, using a roller structure against such surfaces ensures reliable pressing even if there is resistance due to the unevenness.

[0053] In the first to fourth pressing portions 44 to 47 configured as described above, the first to fourth arms 65 to 68 swing up and down as the first to fourth cylinders 77 to 80 extend and retract. 7 and 10, which show the imaging, the third and fourth pressing portions 46 and 47 are not linked but are cylinders that extend and retract in the horizontal direction. This point will be described later.

[0054] A specific folding operation by the folding unit 15 will now be described. [Folding method (4-fold container)] First, a folding method for the four-fold container F will be described using E1 to E6 (drawings) in FIG. 5 and FIG. 6 and F1 to F9 (images) in FIG. The four-fold container F (F1 in FIG. 7) before being folded on the second conveyor belt 16 is lifted by the folding lift 41 to the folding position (E1 in FIG. 5).

[0055] From the state E1 in Fig. 5 (F2 in Fig. 7), when the first and second pressing protrusions 53 and 54 are extended by the first and second cylinders 51 and 52 located on the left and right sides of the container F, respectively, the lock buttons F8 and F9 of the four-fold container F are pressed down. This releases the lock of the first and second locking mechanisms F6 and F7, releasing the connection of the side plates F2 and F3 to the third side plate F4 and the fourth side plate F5, allowing the side plates F2 and F3 to be folded (E2 in Fig. 5, F3 in Fig. 7).

[0056] At this time, the container discrimination means 20 of the control unit 4 in the folding device 100 determines that the container is a four-fold container F equipped with a locking mechanism because the pressing protrusions 53, 54 extend a predetermined amount when the lock button is pressed.

[0057] Then, the link motion of the pressing portions 44, 45 is operated simultaneously, and the first and second rollers 61, 62 fold the first and second side plates F2, F3 downward and inward (E3 in FIG. 5, F4 in FIG. 7). At this time, as shown in E3, the pressing protrusions 53, 54 are pressed by the first and second side plates F2, F3 and can escape inward. Then, when the first and second pressing protrusions 53, 54 are released from the pressure of the first and second side plates F2, F3, they return to their original positions by the first and second coil springs 55, 56, and the pressing portions 44, 45 also return to their original positions (E4 in FIG. 6, F5 in FIG. 7).

[0058] Next, the third and fourth pressing portions 46 and 47 located in the front-to-rear direction of the container F are simultaneously operated in link motion, and the third and fourth rollers 63 and 64 fold the third and fourth side plates F4 and F5 downward and inward (E5 and E6 in Figure 6, F6 and F7 in Figure 7).

[0059] In this way, the folding operation of the four-fold container F is completed. Then, the folded four-fold container F is lowered to the second conveyor belt 16 (F8 in FIG. 7) and conveyed to the next process (F9).

[0060] [Folding method (foldable container)] Next, a folding method for the center-foldable container M will be described with reference to G1 to G6 (drawings) in FIG. 8 and FIG. 9 and H1 to H8 (photographs) in FIG. The center-foldable container M (FIG. 10H1) on the second conveyor belt 16 before being folded is lifted up to the folding position by the folding lift 41 (G1).

[0061] From the state G1 in Fig. 8 (H2 in Fig. 10), as with the four-fold container F, the pressing protrusions 53, 54 are extended by the cylinders 51, 52 located on the left and right sides of the container F, respectively. However, at this time, the center-foldable container M does not have the first and second lock buttons F8, F9. Therefore, the pressing protrusions 53, 54 come into contact with the upper surface of the frame M2 of the center-foldable container M, and their extension stops midway (G2 in Fig. 8, H3 in Fig. 10). For this reason, the stroke of the cylinders 51, 52 with the center-foldable container M is shorter than with the four-foldable container F.

[0062] At this time, the container discrimination means 20 of the control unit 4 in the folding device 100 determines that the container is a center-foldable container M that does not have a locking mechanism because the predetermined amount of extension did not occur when the lock button was pressed by the pressure protrusions 53, 54.

[0063] Then, when the container discriminating means 20 discriminates that the container is a center-folded container M, a folding method different from that used for the four-folded container F described above is carried out in accordance with an instruction from the control unit 4.

[0064] First, the first and second rollers 61 and 62 fold the first and second side plates M3 and M4 upward and inward due to the link movement of the first and second pressing portions 44 and 45 (G3 and G4 in FIG. 8, H4 and H5 in FIG. 10).

[0065] Unlike the case of the four-fold container F (E4 in FIG. 6), instead of immediately returning the rollers 61 and 62, the rollers 61 and 62 hold the first and second side plates M3 and M4 upward, and the third roller 63 of the upstream third pressing unit 46 slightly folds only the third side plate M5 downward and inward (G5 in FIG. 9, H6 in FIG. 10). In other words, the third side plate M5, which is composed of the rotatably connected upper and lower side plates M7 and M8, bends inward. This slight folding causes the upper plates M7 and M9 to bend inward in a V-shape and support the first and second side plates M3 and M4. In this way, of the opposing third and fourth side plates M5 and M6, only the third side plate M5 is folded slightly first.

[0066] Then, the first and second rollers 61, 62 on the left and right sides of the container F return to their original positions (G6 in FIG. 9), and finally, the fourth roller 64 of the fourth pressing unit 47 located downstream folds the fourth side plate M6 downward and inward (G7 in FIG. 9). As a result, the fourth side plate M6, which is made up of the rotatably connected upper and lower plates M9 and M10, is bent inward.

[0067] Then, the third and fourth side panels M5, M6 continue to bend inward until they are completely folded (G7, G8 in FIG. 9, H7 in FIG. 10). In this way, the folding operation of the center-foldable container M is completed. The folded center-foldable container M is then lowered to the second conveyor belt 16 (H8 in FIG. 10) and transported to the next process.

[0068] In this way, when folding the center-foldable container M, of the opposing third and fourth side plates M5, M6, only one of the third side plates M5 is folded a little first, and then the other, the fourth side plate M6, is folded. This is because if the third and fourth side plates M5, M6 were folded simultaneously, the folding might stop midway due to the uniform load, so by providing a time difference between the operation of the third pressing portion 46 and the fourth pressing portion 47, such folding defects are prevented.

[0069] [Stacking discharge unit] Folding device 100 does not discharge containers folded by folding section 15 of folding unit 2 one by one, but discharges a certain number of containers in a stacked state. Therefore, when moving the discharged containers to a predetermined location for storage, the user does not need to stack the folded containers one by one by himself, eliminating the need for stacking work for the user, making folding device 100 more efficient to use.

[0070] In such a stacking and discharging unit 3, the folded containers sent from the folding unit 2 located on the upstream side are stacked in a plurality of containers in the stacking section 17.

[0071] [Stacking section] A stacking method of the stacking section 17 of the stacking and discharging unit 3 will be described with reference to J1 to J6 (drawing) in FIG. 11 and K1 to K4 (photographs) in FIG. The stacking section 17 includes a stacking lift 91 located between two belt conveyors that are the third transport belt 19, and a pair of first and second stacking plates 92, 93. The stacking lift 91 raises and lowers the containers F and M and is movable up and down.

[0072] The stacking plates 92, 93 are pivotally supported so as to be able to open and close by opening and closing operations upward from a horizontal position, as shown at J2, J5. When the stacking plates 92, 93 are pressed upward as shown at J2, they open, allowing containers F, M to pass between the stacking plates 92, 93. When the stacking plates 92, 93 are closed and horizontal as shown at J5, the bottom plates F1, M1 can receive the containers F, M that have descended, and hold the containers F, M.

[0073] The stacking operation in the stacking section 17 will now be described. J1 in Figure 11 and K1 in Figure 12 show a state in which containers F and M stacked in four layers are supported on stacking plates 92 and 93, and the container F before being stacked has been transported to below the stacking plates 92 and 93 by the third conveyor belt 19.

[0074] When the container F before stacking is raised by the stacking lift 91, the stacking plates 92, 93 are pushed upward by this container F, opening it, and at the same time, it pushes up the four previously stacked containers while hitting the bottom of them (J2, J3 in Fig. 11, K2 in Fig. 12).Then, the stacking lift 91 further pushes up the five-tiered container, and when it has passed between the open stacking plates 92, 93 (J4 in Fig. 11, K3 in Fig. 12), it returns the stacking plates 92, 93 to a horizontal state (J5 in Fig. 11, K4 in Fig. 12).

[0075] Then, the stacking lift 91 is lowered, and the five-tiered containers are held on the stacking plates 92, 93 (J6 in FIG. 11). By repeating these operations of J1 to J6, the containers can be stacked one on top of the other.

[0076] [Discharge section] When the number of layers in stacking section 17 reaches a predetermined number (here, 10 layers), the sheets are discharged to discharge section 18 by third conveyor belt 19. This discharge method will be described using L1 to L4 in FIG.

[0077] L1 in Figure 13 shows a state in which containers F and M are stacked 10 high on stacking plates 92 and 93 of the stacking section 17. The stacking lift 91 slightly lifts the 10-high stacked containers (L2), and the stacking plates 92 and 93 open (L3), allowing the stacked containers to pass between the stacking plates 92 and 93. From this state, the ten-tiered containers are lowered to the third conveyor belt 19 (L4), whereby the ten-tiered containers are discharged to the discharge section 18.

[0078] [Method for identifying defective products] Here, the folding device 100 is equipped with a defective product detection means 21 that detects defective containers when a folding failure occurs in the folding section 15 of the folding unit 2. The defective product detection means 21 will be described below. Note that a defectively folded container is a container that cannot be stacked in the stacking section 17 because it is not in a folded state due to deformation of the side panels of the container caused by long-term use or because parts remain inside the container.

[0079] The main parts of the defective product discriminating means will be described using M1 to M3 in Fig. 14. As shown in M1 in Fig. 14, a defective product detector 81 is provided in the folding section 15 of the folding unit 2. This defective product detector 81 uses an optical sensor to detect whether the height of the containers F, M exceeds the height when they are properly folded when the folding process of the containers F, M is completed.

[0080] Then, if the detection result of the defective product detector 81, which is formed by the control unit 4 and the defective product detector 81 forming the defective product discrimination means 21, exceeds the limit, the product is deemed to be defective, and is transported to the discharge unit 18 (M3) without being stacked in the stacking unit 17 (M2).

[0081] In particular, in the folding device 100 of this embodiment, the stacking section 17 in the stacking and discharging unit 3 is configured to move folded containers upward and stack them from below the previously folded container. Therefore, as shown by J6 in Fig. 11 and L1 in Fig. 13, there is a space between the stacked containers and the third conveyor belt 19 through which defective containers can pass. This space makes it possible for defective containers to be transported to the discharging section 18.

[0082] Although the defective product detector 81, which is composed of an optical sensor, has been described as a specific example of the defective product discriminating means, the present invention is not limited to this configuration. The folding device 100 of this embodiment is configured to include first to fourth pressing units 44 to 47 for pressing the side panels of the container inward. Defective containers are created when the side panels do not completely collapse inward due to deformation of the side panels or parts remaining inside the container, making it impossible to fold. Therefore, if the first to fourth pressing units 44 to 47 are unable to move the predetermined amount during folding and stop midway, this means that the side panels did not completely collapse, and the first to fourth pressing units 44 to 47 can also be used as defective product discriminating means. Alternatively, a method of discrimination based on image information acquired by a camera can be adopted.

[0083] As described above, the container folding device of the present invention shown in the above embodiment can distinguish between four-fold containers and center-foldable containers, which have different folding methods, using the container discrimination means, and fold them using different methods. This eliminates the need to separate four-fold containers from center-foldable containers. Furthermore, since there is no need to install both a folding device specifically for four-fold containers and a folding device specifically for center-foldable containers, the installation area for the folding device can be reduced.

[0084] In this embodiment, the container discrimination means 20 focuses on the fact that four-fold containers F have lock buttons F8, F9, while center-fold containers M do not have a lock button, and achieves inexpensive and highly accurate discrimination by discriminating based on the amount of extension of the pressing protrusions 53, 54 that occurs depending on whether or not the lock buttons are pressed by the first and second pressing protrusions 53, 54.

[0085] As another container identification method, for example, there is a method in which the folding lift 41 on which the container is placed can move downward when the container is pressed down at the position of the lock button by the pressing protrusions 53, 54. In other words, when the lock button is pressed down by the pressing protrusions 53, 54, the container does not move downward by the amount of extension caused by the pressing, so this container can be identified as a four-fold container F with lock buttons F8, F9. Conversely, if the lock button is not pressed down by the pressing protrusions 53, 54, the container moves downward by that amount, so this container can be identified as a center-fold container M without lock buttons F8, F9. Also, a method can be adopted in which the folding supply unit 14 is equipped with a camera in the folding unit 15 and the type of container can be identified from image information from the camera.

[0086] Furthermore, in the container folding device of the present invention, the pressing protrusions are capable of tilting inward, so the inward movement of the first side plate and the second side plate is not hindered by the pressing protrusions, thereby reducing the occurrence of improper folding of the container during the folding operation.

[0087] Furthermore, in the container folding device of the present invention, the pressing section has a mechanism in which the roller at the tip that presses swings, so that when the container is transported, the arm can be retracted upward or downward to prevent interference with the transport of the container.

[0088] In the drawings of Figures 5, 6, 8, and 9, the third pressing unit 46 and the fourth pressing unit 47, which are located at the front and rear of the folding unit 15 in the container conveying direction, are shown configured to swing up and down by link movement. On the other hand, in the image illustrations of Figures 7 and 10, the third pressing unit 46 and the fourth pressing unit 47 are configured to extend and retract horizontally. If the pressing units located at the front and rear of the container conveying direction as shown in Figures 7 and 10 are configured to extend and retract horizontally, there is a risk that the pressing units will interfere with conveyance when a tall container is supplied from the folding supply unit 14. On the other hand, if the pressing units located at the front and rear of the container conveying direction are configured to swing up and down, the container can be conveyed with the pressing units positioned at the top. Therefore, in order to be able to accommodate the folding of containers of different heights, it is more preferable that the third pressing portion 46 and the fourth pressing portion 47 are configured to swing up and down by a link movement as shown in Figures 5, 6, 8 and 9.

[0089] Furthermore, since the container folding device of the present invention stacks folded containers upward and discharges them, it is possible to stack them in more layers than if they were stacked downward. Also, since it is equipped with a defective product discrimination means for discriminating defectively folded products, it is possible to remove defectively folded products at an early stage.

[0090] Incidentally, the folding supply unit 14 can also determine the size of a container by installing an optical sensor consisting of a light-emitting element and a light-receiving element, which are used in the defective product discrimination means 21, at a predetermined position. Four-fold containers F and center-foldable containers M are generally standardized and come in different sizes, such as different heights. Therefore, by installing an optical sensor at a predetermined position, the size of the container positioned in the folding supply unit 14 can be determined, and the folding method in the folding unit 15 can be changed depending on the size.

[0091] According to the inventor's testing, four different sizes of containers could be distinguished by installing optical sensors in four locations. Therefore, a total of eight different container sizes can be accommodated, including the four different container sizes and the two types of four-fold containers F and center-fold containers M. To accommodate folding of different sizes of containers F and M, if the container is tall, the height of the vertically movable folding lift 41 of the folding unit 15 can be adjusted to match the height of the container. To accommodate folding of different sizes of containers F and M, for example, larger containers may be accommodated by providing additional pressure units for larger containers in different positions. The pressure units located at the front and rear of the container in the transport direction may be embedded below the second conveyor belt 16 and may swing upward to appear and disappear into the container as needed. [Explanation of symbols]

[0092] 100: Container folding device (folding device) 1: Stacking separation unit 12: Separation part 2: Folding unit 15: Folding section 42, 43: First and second lock pressing parts 53, 54: First and second pressing protrusions 44-47: 1st to 4th pressing parts 3: Stacking discharge unit 17: Stacking section 4: Control unit 20:Container identification method 21: Defective product determination means F: 4-fold container F2~F5: 1st~4th side plate F8, F9: 1st and 2nd lock buttons M: Center-folded container M2: Frame M3~M6: 1st~4th side plate

Claims

1. a four-fold container comprising: a rectangular bottom plate provided at the bottom; first and second side plates facing each other and rotatably attached to the bottom plate at one end; third and fourth side plates facing each other and rotatably attached to the bottom plate at one end; and first and second locking mechanisms respectively provided at the tops of the first and second side plates for locking the third and fourth side plates in a connected state; a folding container comprising: a rectangular bottom plate provided at the bottom; a rectangular frame body provided at the top and having an opening; first and second side plates facing each other and one end of which is rotatably provided on the frame body; and third and fourth side plates facing and adjacent to the first and second side plates and which are foldable; A container folding device for folding a container, A container folding device comprising a container discrimination means for discriminating between the four-fold container and the center-folded container.

2. a first pressing portion that presses the first side plate inward; a second pressing portion that presses the second side plate inward; a third pressing portion that presses the third side plate inward; a fourth pressing portion that presses the fourth side plate inward; a lock pressing portion provided on the first side plate and the second side plate for pressing the lock mechanism; The folding unit comprises:

2. The container folding device according to claim 1, wherein the container discriminating means discriminates based on the pressing action of the lock pressing portion.

3. The lock pressing portion is a rod-shaped pressing protrusion located above the lock mechanism, 3. The container folding device according to claim 2, wherein the tip end of the pressing protrusion is tiltable inward.

4. The folding unit comprises: Furthermore, it is equipped with a container transport section, The first to fourth pressing units are made of arms that swing up and down, 3. The container folding device according to claim 2, wherein a roller is attached to the tip of the arm.

5. a stacking and discharging unit for stacking and transporting folded containers is further provided downstream of the folding unit, 5. The container folding device according to claim 4, wherein the folded containers are stacked by moving the folded containers upward and stacking them from below the previously folded container.

6. The folding unit comprises:

6. A container folding device according to claim 1, further comprising a defective product discriminating means for discriminating defectively folded products.

7. 2. The container folding device according to claim 1, further comprising a stacking separation unit disposed upstream of the folding unit for separating and transporting stacked containers.

8. a four-fold container including a rectangular bottom plate provided at the bottom, first and second side plates facing each other and rotatably attached to the bottom plate at one end, third and fourth side plates facing each other and rotatably attached to the bottom plate at one end, and locking mechanisms provided on the tops of the first and second side plates, respectively, for locking the third side plate and the fourth side plate in a connected state; a folding container comprising: a rectangular bottom plate provided at the bottom; a rectangular frame body provided at the top and having an opening; first and second side plates facing each other and one end of which is rotatably provided on the frame body; and third and fourth side plates facing adjacent to the first and second side plates and capable of being folded; a first pressing portion that presses the first side plate inward; a second pressing portion that presses the second side plate inward; a third pressing portion that presses the third side plate inward; a fourth pressing portion that presses the fourth side plate inward; a lock pressing portion provided on the first side plate and the second side plate for pressing the lock mechanism; A method for folding a container using a folding unit comprising: If the lock pressing unit can press the lock, it is determined that the container to be folded is the four-fold container, If the lock pressing unit cannot press the lock, it is determined that the container to be folded is the center-foldable container, A method for folding a container, characterized in that the first to fourth pressing units are operated to fold the container depending on the result of distinguishing between the four-fold container and the center-folded container.

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