Seal checking device

Abstract

To provide a seal check device that can accurately detect the seal condition of a bag. [Solution] The seal checking device comprises a first guide section 101 and a second guide section 102 positioned on both sides of the bag B on the conveyor 112, a moving mechanism, a contact member 120, a detection unit, and an inspection unit. The moving mechanism moves the first guide section 101 in a direction intersecting the conveying direction to put the bag B into a first state where it is sandwiched between the first guide section 101 and the second guide section 102. The detection unit detects changes in the height position of the contact member 120 that is in contact with the bag B in the first state. Based on the change in the height position of the contact member 120, the inspection unit inspects the seal state of the bag.

Description

Technical Field

[0001] The present invention relates to a seal check device for performing a seal check on a bag.

Background Art

[0002] Conventionally, there has been a device for inspecting a package containing an article and detecting a defective package. For example, in the device of Patent Document 1 (Japanese Patent Application Laid-Open No. 2006-160264), the pressing surface of an air cylinder is applied to the package on the conveyor to press the upper surface of the package. Then, a defective package is detected based on a signal from a sensor connected to the air cylinder.

Summary of the Invention

Problems to be Solved by the Invention

[0003] In the package (bag), there are some in which the amount of gas enclosed together with the article is small and the change in the thickness of the bag when the upper surface is pressed is small. When inspecting such a bag with a small amount of gas enclosed, when the upper surface of the bag is pressed, the pressing part may hit the article in the bag through the packaging film, and there is a risk that a seal defect of the bag cannot be detected.

[0004] An object of the present invention is to provide a seal check device capable of detecting the seal state of a bag favorably.

Means for Solving the Problems

[0005] The seal checking device relating to the first aspect performs a seal check on a bag containing an article and sealed. The seal checking device comprises a conveyor for transporting the bag, a first guide section and a second guide section, a moving mechanism, a contact section, a detection section, and an inspection section. The first guide section and the second guide section are positioned on both sides of the bag on the conveyor. The moving mechanism moves the first guide section horizontally in a direction intersecting the transport direction to bring the bag to a first state. The first state is a state in which the bag is sandwiched between the first guide section and the second guide section. The contact section makes contact with the bag in the first state. The detection section detects changes in the height position of the contact section in contact with the bag. Based on the changes in the height position of the contact section in contact with the bag, the inspection section inspects the seal condition of the bag.

[0006] Here, by putting the bag into the first state, the height (thickness) of the bag can be increased even when the amount of gas inside the bag is small. As a result, the contact point makes contact with the bag without being subjected to force from the items inside the bag, and the sealing condition of the bag can be detected well.

[0007] The seal checking device according to the second perspective is the seal checking device according to the first perspective, further comprising a lifting mechanism for moving the contact portion vertically. The lifting mechanism moves the contact portion to the bag that has been brought to the first state by the moving mechanism, bringing the contact portion into contact with the bag.

[0008] Here, the contact point can be moved vertically using a lifting mechanism, which allows for the automation and speeding up of inspections.

[0009] The seal checking device relating to the third viewpoint is the seal checking device relating to the second viewpoint, wherein the lifting mechanism lowers the contact portion from a position higher than the top surface of the bag in the first state, and brings the contact portion into contact with the top surface of the bag.

[0010] The seal checking device relating to the fourth perspective is a seal checking device relating to either the first or third perspective, wherein the conveyor stops operating when the bag is transported below the contact area. The moving mechanism sets the bag, which has stopped due to the stopping of the conveyor's operation, to the first state. The contact area comes into contact with the bag that has been set to the first state by the moving mechanism.

[0011] Here, the contact part comes into contact with the bag, which has entered the first state through a series of operations by the conveyor and the moving mechanism.

[0012] The seal checking device relating to the fifth viewpoint is a seal checking device relating to the first viewpoint or the third viewpoint, wherein the position of the upper end of the bag, which has been brought to the first state by the first guide portion and the second guide portion, is higher than the position of the upper end of the bag before it was brought to the first state.

[0013] The seal checking device relating to the sixth aspect is the seal checking device relating to the third aspect, wherein the lifting mechanism lowers the contact portion to a position lower than the upper end of the first guide portion, and brings the contact portion into contact with the upper surface of the bag.

[0014] The seal checking device relating to the seventh viewpoint is a seal checking device relating to the second or third viewpoint, further comprising a control unit and an operating unit. The control unit controls the operation of the transport conveyor, the moving mechanism, and the lifting mechanism. The operating unit allows the start timing and stop timing of the operation of the transport conveyor, the moving mechanism, and the lifting mechanism to be set as parameters. [Effects of the Invention]

[0015] According to the seal checking device of the present invention, the seal condition of the bag can be accurately detected in order to return the bag to a first state. [Brief explanation of the drawing]

[0016] [Figure 1] This is a side view of a seal checking device according to one embodiment of the present invention. [Figure 2] This is a partially enlarged view of Figure 1. [Figure 3]It is a perspective view of the main part of the seal check device. [Figure 4] It is a control block diagram of the seal check device. [Figure 5] It is a control flow diagram of seal check. [Figure 6] It is a control flow diagram of seal check. [Figure 7A] It is a diagram showing the relative positions of the bag before reaching the first state, the first guide member, and the second guide member. [Figure 7B] It is a diagram showing the relative positions of the bag after reaching the first state, the first guide member, and the second guide member. [Figure 8] It is a diagram when the contact member shown in Fig. 7B is replaced with another contact member having a different thickness. [Figure 9] It is a side view of the seal check device according to Modification D without a stopper. [Figure 10] It is a side view of the seal check device according to Modification D. [Figure 11] It is a side view of the seal check device according to Modification D.

Embodiments for Carrying Out the Invention

[0017] Hereinafter, embodiments of the present invention will be described while referring to the drawings. The following embodiments are specific examples of the present invention and do not limit the technical scope of the present invention. Also, in each figure, the same or corresponding parts are denoted by the same reference numerals, and redundant explanations are omitted.

[0018] (1) Overall Configuration of the Seal Check Device The seal check device 100 is a device that performs a seal check on a bag B formed by heat-sealing a packaging film. The bag B is a bag generated by a pillow packaging machine (not shown) installed upstream and having an article P and a gas A enclosed therein. The bag B conveyed to the seal check device 100 is enclosed with the gas A inside during the process of being generated by heat-sealing the ends in a state where the article P is accommodated in the upstream packaging machine. The gas A is, for example, air or nitrogen.

[0019] The seal check device 100 mainly includes a transport conveyor 110 for transporting the bag B, a first guide member 101 and a second guide member 102, a moving mechanism 105, a contact member 120 that contacts the bag B, a lifting mechanism 130 for changing the height position of the contact member 120, a detection unit 140 for detecting the displacement amount of the height position of the contact member 120, an inspection unit 150 for inspecting the seal state of the bag B, a control unit 160 for controlling the lifting mechanism 130, and an operation / display unit 190.

[0020] (2-1) Transport conveyor The transport conveyor 110 is a group of conveyors for carrying in, transporting, and discharging the bag B in the seal check device 100, and is composed of a first conveyor 111, a second conveyor 112, and a third conveyor 113. These first conveyor 111, second conveyor 112, and third conveyor 113 are arranged in series in order from the right side of FIG. 1.

[0021] Above the upstream portion from the first conveyor 111 to the second conveyor 112, fixed guide members 116, 117 are provided. As shown in FIG. 3, the fixed guide members 116, 117 located on both sides of the transport path of the bag B are wall members that guide the bag B into the space below the contact member 120 described later. The fixed guide members 116, 117 are configured to be movable in the width direction of the transport conveyor 110, but the adjustment is manual, and the position and posture are fixed during the operation of the seal check device 100.

[0022] (2-2) First guide member and second guide member As shown in Figure 3, the first guide member 101 and the second guide member 102 are positioned on both sides of bag B on the second conveyor 112 of the conveyor belt 110. The first guide member 101 is located downstream of the fixed guide member 116, and the second guide member 102 is located downstream of the fixed guide member 117. The first guide member 101 and the second guide member 102 are fixed to the tips of air cylinders 105a and 105b, respectively, which constitute the moving mechanism 105, and are moved by the air cylinders 105a and 105b in a direction perpendicular to the conveying direction (the width direction of the conveyor belt 110). The horizontal white arrows in Figure 7B indicate the direction in which the first guide member 101 and the second guide member 102 move along the width direction of the second conveyor belt 112 and move toward the center.

[0023] (2-3) Movement mechanism The moving mechanism 105 is a mechanism for moving the first guide member 101 and the second guide member 102, and mainly comprises air cylinders 105a and 105b, and valves 106 (see Figure 4) for turning the supply of air to them on and off. Air cylinder 105a reciprocates the first guide member 101 in the width direction of the second conveyor 112. Air cylinder 105b reciprocates the second guide member 102 in the width direction of the transport conveyor 110. As a result, the moving mechanism 105 switches between two positions in the width direction: an outer position and an inner position for the first guide member 101 and the second guide member 102.

[0024] Figure 7A shows the state in which both the first guide member 101 and the second guide member 102 are in the outer position. Figure 7B shows the state in which both the first guide member 101 and the second guide member 102 are in the inner position. In the state shown in Figure 7B, bag B is sandwiched between the first guide member 101 and the second guide member 102, and the first guide member 101 and the second guide member 102 are pressing against bag B. This state shown in Figure 7B will be referred to as the first state below. As will be described later, in the seal check, bag B is put into the first state, but the height position H12 of the upper end of bag B in the first state shown in Figure 7B is higher than the height position H11 of the upper end of bag B before it is put into the first state (see Figure 7A).

[0025] (2-4) Contact Member The contact member 120 is a member that contacts the upper surface of bag B and applies pressure from above during seal check. As shown in Figures 3 and 7B, the contact member 120 is located in the space above the second conveyor 112 of the transport conveyor 110. More specifically, the contact member 120 is located in the space above the downstream part of the second conveyor 112 (the part closer to the third conveyor 113). The contact member 120 contacts the upper surface of bag B, which has been transported by the second conveyor 112 and has reached the first state described above, from above. The contact member 120 is made of metal, resin, or rubber.

[0026] (2-5) Lifting mechanism The lifting mechanism 130 is a mechanism for moving the contact member 120 in the vertical direction to change the height position of the contact member 120. The lifting mechanism 130 mainly comprises a support 133 to which the contact member 120 is fixed, a horizontal link 132 for changing the height position of the support 133 while maintaining a horizontal state, and a servo motor 138 for moving a lever at the bottom of the horizontal link 132.

[0027] The support 133 is fixed to the upper part of the horizontal link 132 and extends elongated in a direction perpendicular to the conveying direction of bag B. The support 133 has two ends 133a, 133a fixed to the horizontal link 132, a connecting part 133b connecting the two ends 133a, 133a, and a support part 133c fixed to the longitudinal center of the connecting part 133b. The contact member 120 is fixed to the support part 133c. The contact member 120 fixed to the support 133 can be removed from the support 133. In place of the contact member 120 shown in Figure 3, smaller contact members, contact members of different shapes, or contact members of different heights can also be attached to the support part 133c. This selection is made manually by the user according to the type (size, etc.) of bag B.

[0028] In the seal check, the lifting mechanism 130 lowers the contact member 120 to a position lower than the upper ends of the first guide member 101 and the second guide member 102, as shown in Figure 7B, and brings the contact member 120 into contact with the upper surface of the bag B. As shown in Figure 3, the height position of the contact member 120 before lowering is higher than the upper surface of the bag B in the first state shown in Figure 7B, and also higher than the upper ends of the first guide member 101 and the second guide member 102.

[0029] (2-6) Detection unit The detection unit 140 detects the amount of displacement of the height position of the contact member 120 when the bag B is in contact with the contact member 120. As shown in Figure 4, the detection unit 140 has an encoder 145, which outputs the amount of rotation of the rotation axis of the servo motor 138 of the lifting mechanism 130. This output of the encoder 145 is read by the computer 200, which will be described later, and is treated as the amount of displacement of the height position of the contact member 120. In other words, the detection unit 140 detects the change in the height position of the contact member 120 that is in contact with the bag B.

[0030] (2-7) Inspection and Control Units The inspection unit 150 and the control unit 160 are implemented by the computer 200 and are functional units within the program executed by the computer 200 in the seal check device 100. The computer 200 includes a control arithmetic unit 201 and a storage device 202 (see Figure 10). The control arithmetic unit 201 can use a processor such as a CPU or GPU. The control arithmetic unit 201 reads the program stored in the storage device 202 and performs predetermined image processing and calculation processing according to this program. Furthermore, the control arithmetic unit 201 can write the calculation results to the storage device 202 or read the information stored in the storage device 202 according to the program. The inspection unit 150 and the control unit 160 control the operation of the transport conveyor 110, the moving mechanism 105, the lifting mechanism 130, and so on.

[0031] The inspection unit 150 inspects the sealing state of bag B by comparing the amount of displacement detected by the detection unit 140 with a preset threshold. In other words, the inspection unit 150 inspects the sealing state of bag B based on the change in the height position of the contact member 120 that is in contact with bag B.

[0032] The inspection unit 150, in cooperation with the control unit 160, which is running on the same computer 200, inspects the sealing condition of bag B. When bag B is transported to the downstream end of the second conveyor 112, the inspection unit 150 and the control unit 160 stop the operation of the second conveyor 112. Then, the inspection unit 150 and the control unit 160 send an instruction to the moving mechanism 105 to return bag B, which has stopped due to the stopping of the second conveyor 112, to the first state. As a result, the contact member 120 comes into contact with bag B, which has been returned to the first state by the moving mechanism 105.

[0033] (2-8) Operation / display section As shown in Figures 1 and 4, the operation / display unit 190 is located on top of the seal check device 100 and is a touch panel display connected to the computer 200. The user uses the operation / display unit 190 to input and set the start and stop timings of the transport conveyor 110, the moving mechanism 105, and the lifting mechanism 130 as parameters.

[0034] (2-9) Control flow for seal check The inspection unit 150 and the control unit 160 control the servo motor 138 of the lifting mechanism 130 according to the control flow shown in Figures 5 and 6. Hereafter, the control entity may be described as either the inspection unit 150 or the control unit 160, but as mentioned above, the inspection unit 150 and the control unit 160 are functional parts of the program executed by the control calculation unit 201 and are an integrated unit, so the control entity may be read as "inspection unit 150 and control unit 160" respectively.

[0035] Before controlling the seal check, the seal check device 100, after startup, has a control unit 160 that determines control parameters based on initial information about bag B entered by the user from the operation / display unit 190. Specifically, when the product number of the item P contained in bag B to be inspected is specified, the control calculation unit 201 reads the corresponding various control parameters from the storage device 202 and sets the operating conditions. The initially set operating conditions include the timing of the start of the descent of the contact member 120 after detection of bag B being brought in, based on the size of bag B, the material of bag B, etc., the first and second height positions which are standby positions, and the second force described later.

[0036] When operation begins and bag B is brought into the seal checking device 100, the seal checking of bag B in the seal checking device 100 begins. When bag B to be inspected is on the first conveyor 111, the contact member 120 is stationary at the first height position, which is the standby position (step S11). The first height position is higher than the height position of the upper end of bag B in the first state shown in Figure 7B.

[0037] When bag B is transported from the first conveyor 111 to the downstream section of the second conveyor 112 (the space below the contact member 120), an inspection start instruction is generated, and the control unit 160 sends operation instructions to the moving mechanism 105 and the lifting mechanism 130 (steps S12 to S14). Sensors that detect the passage of bag B are installed near the boundary between the first conveyor 111 and the second conveyor 112. When bag B has been transported to the space directly below the contact member 120 and the transport conveyor 110 has stopped, the control unit 160 generates an inspection start instruction and starts the inspection (seal check).

[0038] In step S13, the control unit 160 sends an operation command to the moving mechanism 105 to move the first guide member 101 and the second guide member 102, bringing bag B into a first state where it is sandwiched between the first guide member 101 and the second guide member 102. In the first state, as shown in Figure 7B, bag B has a narrower width than bag B before entering the first state (see Figure 7A), but its thickness increases, and the upper end of bag B is at height position H2.

[0039] In step S14, the control unit 160 changes the force (torque) applied to the contact member 120 from the servo motor 138 to lower the contact member 120 from the first height position to the second height position. The second height position is initially set to a position slightly lower than the height position H12 of the upper end of bag B (see Figure 7B).

[0040] The contact member 120 is subjected to a downward force due to gravity, which is proportional to the mass of the support 133 and itself, and an upward force from the servo motor 138. When the upward force becomes smaller than the downward force, the contact member 120 descends. In other words, when the contact member 120 is stationary at the first height position, which is the standby position, an upward force from the servo motor 138 acts on it that counteracts the gravity of the contact member 120, the horizontal link 132, the support 133, etc. By weakening the force (torque) from the servo motor 138, the contact member 120 descends. Due to the action of the horizontal link 132, the contact member 120 moves diagonally downwards when descending.

[0041] Furthermore, if the contact member 120 contacts bag B after bag B has entered the first state, steps S13 and S14 may be performed simultaneously or with a time difference.

[0042] In step S15, the control unit 160 determines whether the contact member 120 has descended to the second height position, that is, whether the contact member 120 has descended to a height position where it contacts the upper end of bag B. The height position of the contact member 120 is calculated by the control unit 160 based on the output from the encoder 145 of the detection unit 140. The control unit 160 determines whether the contact member 120 has descended to the second height position based on whether a predetermined time t0 has elapsed since the contact member 120 was lowered.

[0043] When the control unit 160 determines that the contact member 120 has descended to the second height position, it proceeds to step S16 and changes the upward force that the servo motor 138 has been applying to the contact member 120 from the first force to the second force (a force smaller than the first force). This makes the downward pressure applied from the contact member 120 to the bag B a value suitable for seal checking. A certain amount of pressure is required for seal checking.

[0044] In step S17, the inspection unit 150 determines whether the displacement of the contact member 120 is less than a threshold. The inspection unit 150 calculates the difference between the height position of the contact member 120 after the first time t1 has elapsed since it was determined in step S15 that the contact member 120 has descended to the second height position, and the height position of the contact member 120 after the second time t2 has elapsed, and uses this difference as the displacement of the contact member 120. The height position of the contact member 120 is calculated based on the output from the encoder 145 of the detection unit 140. If there is no seal leakage in bag B, the displacement of the contact member 120 is small, and if there is a seal leakage in bag B, the displacement of the contact member 120 is large.

[0045] If the inspection unit 150 determines that the displacement of the contact member 120 is less than the threshold, in step S18 the inspection unit 150 determines that the sealing condition of bag B is good. If the inspection unit 150 determines that the displacement of the contact member 120 is greater than or equal to the threshold, in step S19 the inspection unit 150 determines that the sealing condition of bag B is poor.

[0046] (3) Features (3-1) In the seal checking device 100 of this embodiment, even when the amount of gas A in bag B is small, as shown in Figure 7A, the height dimension (thickness) of bag B can be increased by putting bag B into the first state (see Figure 7B). As a result, the contact member 120 comes into contact with bag B without the contact member 120 receiving force from the article P inside bag B, and the seal state of bag B can be detected well.

[0047] In other words, the seal checking device 100 can generate a large (high) layer of gas A above the article P inside bag B, as shown in Figure 7B, by bringing bag B to the first state. Therefore, even if the thickness of the gas layer above the article P in bag B before it reaches the first state is thin, a good seal check can be performed. For example, if the present invention is applied to bags that pillow-package rice balls or bags that pillow-package tea bags, these bags can be goodly sealed.

[0048] (3-2) In the seal checking device 100 of this embodiment, the contact member 120 is moved vertically by the lifting mechanism 130, thereby enabling the automation and high-speed inspection of seal checks.

[0049] (4) Variations (4-1) Variation A In the above embodiment, fixed guide members 116 and 117 are provided from the first conveyor 111 to the second conveyor 112. These fixed guide members 116 and 117 are simply plate members, but instead, rollers with a rotation axis along the vertical direction may be arranged in a series in the conveying direction to form side walls (guides) so as not to obstruct the conveyance of the bags B as much as possible. Alternatively, instead of the fixed guide members 116 and 117, a belt-type guide mechanism that moves at the same speed as the conveying conveyor 110 may be provided.

[0050] (4-2) Modification B In the above embodiment, in step S15, the control unit 160 determines whether the contact member 120 has descended to the second height position based on whether a predetermined time t0 has elapsed since the contact member 120 was lowered. However, instead, the fact that the contact member 120 has descended to the second height position may be detected by a photoelectric sensor.

[0051] (4-3) Modification C In the above embodiment, two guide members, a first guide member 101 and a second guide member 102, are provided. However, only one of them may be provided, and the other may be a fixed side wall. Alternatively, one of the first guide member 101 and the second guide member 102 may be manually adjustable, while the other may be moved by an air cylinder or an electric ball screw.

[0052] (4-4) Modification D In the above embodiment, the contact member 120 fixed to the support 133 is made detachable from the support 133, making it possible to attach contact members of different shapes or heights to the support portion 133c of the support 133 instead of the contact member 120 shown in Figure 3. For example, when performing a seal check on a bag B1 that contains a flat item and has a small height, as shown in Figure 8, a contact member 120a with a larger height can be attached to the support 133 instead of the contact member 120 to perform the seal check.

[0053] However, depending on the height of bag B, the height of contact members 120 and 120a, and the configuration of the horizontal link 132 of the lifting mechanism 130, it is conceivable that replacing contact member 120a with a contact member 120 of a different height may cause, for example, the support 133 of the lifting mechanism 130 to interfere with the frame 100a (see Figure 9). In the seal checking device according to this modified example, a frame 100a as a housing is provided as shown in Figures 9 to 11.

[0054] If the frame 100a is located in a place where interference may occur, it is preferable to provide a stopper 132a that restricts the movement of the horizontal link 132 of the lifting mechanism 130, as shown in Figure 10, in order to prevent interference with the frame 100a. This prevents interference with the frame 100a even when a contact member 120 with a small height dimension is attached to the support 133. Even when a contact member 120a with a large height dimension is attached to the support 133 with the stopper 132a provided, the stopper 132a does not function, but as shown in Figure 11, no interference occurs between the support 133 and the frame 100a.

[0055] Note that the side view of the seal check device according to this modified example shown in Figures 9 to 11 is a side view from the opposite side to that of Figures 1 and 2, and the arrangement of the conveyor belts 110 is also reversed compared to Figures 1 and 2. In the side view of the seal check device shown in Figures 9 to 11, the first conveyor belt 111, the second conveyor belt 112, and the third conveyor belt are arranged in series from left to right.

[0056] (4-5) Modification E In the above embodiment, the moving mechanism 105 moves the first guide member 101 and the second guide member 102 horizontally in a direction perpendicular to the conveying direction of bag B (the width direction of the conveying conveyor 110). That is, the direction of movement of the first guide member 101 and the second guide member 102 is perpendicular to the conveying direction of bag B.

[0057] However, the direction of movement of the first guide member 101 and the second guide member 102 may be in a direction that is 80° or 70° inclined with respect to the conveying direction of bag B in a plan view. The direction of movement of the first guide member 101 and the second guide member 102 may be determined according to the shape of bag B, and it is preferable that it is in a direction that increases the thickness of bag B in the first state. [Explanation of Symbols]

[0058] 100 Seal Check Device 101 First guide member 102 Second guide member 105 Moving mechanism 110 Conveyor 120 Contact Member 130 Lifting mechanism 140 Detection unit 150 Inspection Department 160 Control Unit 190 Operation / display section 200 Computers A gas B bag P Goods [Prior art documents] [Patent Documents]

[0059] [Patent Document 1] Japanese Patent Publication No. 2006-160264

Claims

1. A seal checking device that performs a seal check on a bag containing and sealed articles, A conveyor for transporting the aforementioned bags and The first guide section and the second guide section are arranged on both sides of the bag on the conveying conveyor, A moving mechanism that moves the first guide portion horizontally in a direction intersecting the transport direction to place the bag in a first state where it is sandwiched between the first guide portion and the second guide portion, The contact portion that contacts the bag in the first state, A detection unit for detecting changes in the height position of the contact portion in contact with the bag, An inspection unit that inspects the sealing state of the bag based on the changes detected by the detection unit, A seal checking device equipped with the following features.

2. A lifting mechanism for moving the contact portion in the vertical direction, Furthermore, The lifting mechanism moves the contact portion to bring the bag into contact with the bag, in the case of the bag that has been brought into the first state by the moving mechanism. The seal checking device according to claim 1.

3. The lifting mechanism lowers the contact portion from a position higher than the upper surface of the bag in the first state, and brings the contact portion into contact with the upper surface of the bag. The seal checking device according to claim 2.

4. The conveyor stops operating when the bag is transported to below the contact area. The moving mechanism returns the bag, which has stopped due to the cessation of the operation of the conveyor belt, to the first state. The contact portion comes into contact with the bag, which has been brought into the first state by the moving mechanism. A seal checking device according to any one of claims 1 to 3.

5. The position of the upper end of the bag, which is brought to the first state by the first guide portion and the second guide portion, is higher than the position of the upper end of the bag before it was brought to the first state. A seal checking device according to any one of claims 1 to 3.

6. The lifting mechanism lowers the contact portion to a position lower than the upper end of the first guide portion, and brings the contact portion into contact with the upper surface of the bag. The seal checking device according to claim 3.

7. A control unit that controls the operation of the conveying belt, the moving mechanism, and the lifting mechanism, An operating unit for setting the start timing and stop timing of the operation of the transport conveyor, the moving mechanism, and the lifting mechanism as parameters, To further enhance The seal checking device according to claim 2 or 3.

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