Top seal packaging seal leak inspection device

Abstract

To provide a seal leak inspection device for top-seal packaging that can detect defective products accurately and in a short time. [Solution] The seal leak inspection device 10 for top-seal packaging of the present invention is a seal leak inspection device for top-seal packaging in which the top opening of a container 12 is covered and sealed with a film, A conveyor 20 transports the container 12 to the inspection position, A stop plate 32 that moves forward and backward in a direction perpendicular to the conveying direction of the conveyor belt 20 in front of the inspection position, and a shutter 30 equipped with a cylinder mechanism 34 that moves the stop plate 32 forward and backward, A stopper 40 is provided behind the inspection position, which contacts the shutter 30 to stop the container 12 by sandwiching it between the front and back. The device is characterized by having a pressing head 50 that presses the top seal packaging of the container 12 at the aforementioned inspection position.

Description

Technical Field

[0001] The present invention relates to a seal leak inspection device for top-seal packaging in which the upper surface opening of a container is sealed with a film.

Background Art

[0002] There is top-seal packaging in which a formed container is filled with a product and the upper surface opening is sealed with a film serving as a lid (for example, disclosed in Patent Document 1). Top-seal packaging is becoming more widely used because it has higher sealing performance than conventional overlapping packaging of foamed trays, enables gas filling, and can reduce the amount of plastic used. For containers packaged with top-seal, seal leak inspection is performed at the final process of the production line to inspect for leaks of gas or air due to seal defects or minute pores.

[0003] Conventional seal leak inspection devices have been performed in the following steps. (1) At an inspection position on a conveyor that conveys a top-seal packaged container (a position below the pressing head on the conveyor), a shutter arranged in front of the inspection position is projected upward to contact the front of the container and stop it. (2) After the container stops, the pressing head is lowered from above to press the top-seal packaging with a predetermined pressure. Seal defects and the like are detected based on the measured value of the strain sensor of the pressing head. (3) After inspection, the pressing head is raised, the front shutter is lowered, and the container is conveyed. Defective products are excluded from the conveyor.

[0004] However, in a conventional seal leak inspection device, when a container conveyed at a predetermined speed is stopped at an inspection position on the conveyor by a front shutter, it is pushed back by the reaction of the collision and the container is displaced from the inspection position. After that, it takes time until the rebounding container is conveyed by the conveyor and stops again by the shutter. Until the container stabilizes at the inspection position, the pressing head cannot be lowered to press the top-seal packaging, so there is a problem that the inspection time required for each container is lengthened. [Prior art documents] [Patent Documents]

[0005] [Patent Document 1] Japanese Patent Publication No. 2019-55803 [Overview of the Initiative] [Problems that the invention aims to solve]

[0006] The problem that this invention aims to solve is to provide a seal leak inspection device for top-seal packaging that can detect defective products accurately and quickly, in view of the problems of the prior art described above. [Means for solving the problem]

[0007] As a first means to solve the above problems, the present invention provides a seal leak inspection device for top-seal packaging in which the top opening of a container is covered and sealed with a film, A conveyor for transporting the container to the inspection position, A stop plate that moves back and forth in a direction perpendicular to the conveying direction of the conveyor in front of the inspection position, and a shutter equipped with a cylinder mechanism for moving the stop plate back and forth, A stopper that contacts the front and rear of the container between itself and the shutter behind the inspection position to stop it, The objective is to provide a seal leak inspection device for top-seal packaging, characterized by having a pressing head that presses the top-seal packaging of the container at the aforementioned inspection position. According to the first method described above, the container can be positioned at the inspection location in a short time, the inspection time per container can be reduced, and defective top-seal packaging can be detected with high accuracy.

[0008] As a second means for solving the above problem, the present invention provides that in the first means, the stopper is The objective is to provide a seal leak inspection device for top-seal packaging, characterized in that a claw is biased toward the container on the conveying conveyor, the claw is pushed back in the opposite direction of biasing by the container during transport, and at the inspection position after the container has passed, the claw protrudes in the biasing direction and contacts the rear of the container. According to the second method described above, the container is not pushed backward by the impact of contact with the shutter at the inspection position, and the container can be positioned at the inspection position in a short amount of time.

[0009] As a third means to solve the above problems, the present invention provides a seal leak inspection device for top-seal packaging, characterized in that, in the second means, the push head is equipped with a spring that presses the top-seal packaging between itself and a cylinder that moves the head up and down. According to the third method described above, the pressing force of the pressing head that presses the top-seal packaging at a predetermined pressure can be easily fine-tuned compared to the conventional cylinder mechanism, making it possible to detect minute sealing defects and minute voids.

[0010] As a fourth means to solve the above problems, the present invention provides a seal leak inspection device for top-seal packaging, characterized in that, in the third means, the cylinder of the push head extends at the inspection position and contacts the top-seal packaging of the container, the spring contracts and then the extension of the cylinder is stopped, and the amount of extension of the spring after a predetermined time has elapsed is measured to determine whether or not there is a seal leak. According to the fourth method described above, minute seal defects and minute voids can be detected more effectively than with conventional load cell-based load measurement. [Effects of the Invention]

[0011] According to the present invention, a seal leak inspection device can be realized that can inspect top-seal packaging with high detection accuracy in a short amount of time. [Brief explanation of the drawing]

[0012] [Figure 1] This is a schematic diagram of the configuration of the seal leak inspection device for top-seal packaging according to the present invention. [Figure 2] This is an explanatory diagram of the push head. [Figure 3] This is an explanatory diagram showing the relationship between the vertical movement of the push head during inspection and time. [Figure 4] This is a process diagram of the seal leak inspection device for top-seal packaging according to the present invention. [Modes for carrying out the invention]

[0013] An embodiment of the seal leak inspection device for top-seal packaging of the present invention will be described in detail below with reference to the drawings. In this embodiment, "front" refers to the downstream side (rear side when the inspection position is used as the reference) along the conveying direction of the conveyor, and "rear" refers to the upstream side (front side when the inspection position is used as the reference) is used. The container to be inspected has a container body with an open top surface that stores contents inside, and the upper part of the container body has a flange formed by protruding laterally. The top opening is covered with a film and sealed in top-seal packaging.

[0014] [Top-seal packaging seal leak inspection device 10] Figure 1 is a schematic diagram of the configuration of the seal leak inspection device for top-seal packaging according to the present invention, where (1) shows the state when the container is not pressed and (2) shows the state when the container is pressed. The seal leak inspection device 10 for top-seal packaging of the present invention is a seal leak inspection device for a top-seal packaging 14 in which the upper surface opening of a container 12 is covered and sealed with a film. It includes a conveyor 20 for transporting the container 12 to an inspection position, a stop plate 32 that moves forward and backward in a direction orthogonal to the transport direction of the conveyor 20 in front of the inspection position, a shutter 30 provided with a cylinder mechanism 34 for moving the stop plate 32 forward and backward, a stopper 40 that contacts and stops the front and rear of the container 12 between it and the shutter 30 behind the inspection position, and a push head 50 for pressing the top-seal packaging of the container 12 at the inspection position. In this embodiment, the inspection position is the position on the conveyor 20 where the push head moves forward and backward, in other words, the position below the push head 50 on the conveyor.

[0015] The conveyor 20 is a conveyor that transports one by one the containers 12 with the top-seal packaging 14 applied to their upper surface openings in the previous process to the inspection position at a predetermined speed. The shutter 30 includes a stop plate 32 that moves forward and backward in a direction orthogonal to the transport direction of the conveyor 20, and a cylinder mechanism 34 for moving the stop plate 32 forward and backward. The stop plate 32 is a plate for stopping the container 12 at the inspection position of the conveyor 20. The stop plate 32 is connected to the cylinder mechanism 34 and is configured to be able to move forward and backward from below to above the conveyor 20 in front of the inspection position. Based on the sensor signal when the container 12 passes through a predetermined position of the conveyor 20, the stop plate 32 can extend and move to protrude so as to block above the conveyor 20, contact the front of the container 12, and stop the container at the inspection position. After the inspection, according to the sensor signal, the stop plate 32 moves backward below the conveyor 20, and the container 12 can be transported from the inspection position.

[0016] The stopper 40 is composed of a claw 42, a spring 44, and a support 46. The support 46 is arranged in front of the inspection position on the conveyor 20 and supports the spring 44 and the claw 42. The claw 42 is rotatably supported at the rear end by the support 46, and the tip is a member configured to be swingable in a direction approaching or separating from the conveyor 20. The spring 44 is connected between the support 46 and the claw 42 and is an elastic body that biases the swinging claw 42 in a direction approaching the conveyor 20. When the container 12 passes on the conveyor 20, the claw 42 contacts the top seal packaging of the container 12 and is pushed back in a direction away from the conveyor 20. When the container 12 is conveyed to the inspection position, the contact with the top seal packaging is released, and it is arranged at a position protruding toward the conveyor 20 by the biasing force of the spring 44. According to such a stopper 40, after the container 12 passes, it can be caught by the flange of the container and the container 12 between it and the shutter 30 can be sandwiched without displacement. The stopper 40 of the present embodiment is arranged above the conveyor 20, but the position of the stopper is not limited to this, and it may be arranged so as to contact the side wall of the container 12 to be conveyed.

[0017] Figure 2 is an explanatory diagram of the pressing head, where (1) shows the state where the container is not being pressed, and (2) shows the state where the container is being pressed. The pressing head 50 serving as the inspection unit includes a cylinder unit 52, a spring 54, and a proximity sensor 56. The cylinder unit 52 moves the pressing head 50 at the lower end up and down toward the container 12 on the conveyor 20. A plurality of springs 54 are attached to a casing connected to the rod of the cylinder unit and are connected above the pressing head 50. The spring 54 biases the pressing head 50 downward. A set collar 55 is attached to one of the springs 54 on the shaft. The set collar 55 moves forward and backward in accordance with the extension of the spring 54. The proximity sensor 56 is arranged above the set collar 55 and is an inductive sensor that incorporates a coil spring to generate a magnetic field and detects the set collar 55. The push head 50 is a component that contacts the top-seal packaging and is configured to move forward and backward in a direction toward or away from the conveyor belt 20 by the cylinder portion 52. By using polyacetal (POM) as the material for the push head 50, it is easy to process and its surface can be made smooth. The planar shape of the push head 50 that contacts the container 12 is formed to be almost the same as the shape of the top-seal packaging, and is formed to be slightly smaller than the top-seal packaging.

[0018] The judgment unit 60 is electrically connected to the proximity sensor 56. The judgment unit 60 measures the amount of spring extension after the cylinder mechanism of the push head 50 extends at the inspection position, contacts the top seal packaging of the container 12, and continues to press for a predetermined time, in order to determine whether there is a seal leak. Figure 3 is an explanatory diagram showing the relationship between the vertical movement of the push head and time during inspection. In the figure, the vertical axis represents the movement of the push head, and the horizontal axis represents time. During inspection, the cylinder part 52 extends and the push head 50 descends (1). The push head 50 descends until it contacts the top seal packaging of the container and the spring 54 contracts, stopping the cylinder part 52 and pressing with a predetermined pressure (2). In the case of a good product, there is no extension of the spring 54 during pressing and no movement of the push head 50 (A). On the other hand, in the case of a defective product, the spring 54 extends due to air or gas leakage from the top seal packaging during pressing (B). The proximity sensor 56 measures (C) and (D) during pressing, and the judgment unit 60 takes the difference between them. If there is no difference, it is determined to be a good product; if a difference occurs, it is determined to be a defective product.

[0019] [Effect] The inspection method using the seal leak inspection device for top-seal packaging of the present invention, configured as described above, will be explained below. Figure 4 is a process diagram of the seal leak inspection device for top-seal packaging of the present invention. (Step 1) The containers 12, which are top-sealed, are transported to the inspection position by the conveyor belt 20. (Step 2) As the container 12 passes under the stopper 40, the claws 42 contact the top seal packaging and are pushed back in the opposite biasing direction, while the container 12 is being transported.

[0020] (Step 3) The stop plate 32 of the shutter 30, positioned in front of the inspection position, protrudes, stopping the container 12 at the inspection position. Simultaneously, the claws 42 that the container 12 has passed over protrude in the biasing direction and catch on the flange at the rear end of the container 12. As a result, the shutter 30 and stopper 40 support the container 12 by sandwiching it at the inspection position, allowing for quick positioning. (Step 4) The cylinder portion 52 extends so that the push head 50 contacts the top seal packaging, and after the spring contracts, the extension of the cylinder portion stops, and the push head 50 presses the top seal packaging of the container 12 with a predetermined pressure for a predetermined time. The determination unit 60 calculates the amount of extension of the spring 54 after a predetermined time has elapsed and determines that the product is good if the amount of movement of the push head 50 is 0, and that it is defective if there is any movement.

[0021] (Step 5) After inspection, the shutter 30 retracts and the container 12 is transported from the inspection position. The next container 12 is then transported to the inspection position. (Step 6) If a defective product is detected, the subsequent discharge pusher 70 removes the defective product from the conveyor belt 20.

[0022] According to this invention, by finely adjusting the pressing force of the pressing head with a spring, even small holes can be detected with high accuracy. Furthermore, by clamping the container with a shutter and a stopper, the container can be quickly positioned at the inspection location, realizing a seal leak inspection device that can inspect top-seal packaging in a short time. Preferred embodiments of the present invention have been described above. However, the present invention is not limited in any way to the above embodiments, and various modifications are possible without departing from the spirit of the invention. Furthermore, the present invention is not limited to the combinations shown in the embodiments, but can be implemented using various combinations. [Explanation of symbols]

[0023] 10. Top-seal packaging seal leak inspection device 12 containers 14. Top-seal packaging 20 Conveyor 30 shutters 32 Stop plate 34 Cylinder mechanism 40 Stopper 42 claws 44 Springs 46 Support 50 Push Heads 52 Cylinder section 54 Spring 55 Set Colors 56 Proximity Sensor 60 Judgment section 70 Discharge Pusher

Claims

1. A seal leak inspection device for top-seal packaging in which the top opening of a container is covered and sealed with a film, A conveyor for transporting the container to the inspection position, A stop plate that moves back and forth in a direction perpendicular to the conveying direction of the conveyor in front of the inspection position, and a shutter equipped with a cylinder mechanism for moving the stop plate back and forth, A stopper that contacts the front and rear of the container between itself and the shutter behind the inspection position to stop it, A seal leak inspection device for top-seal packaging, characterized by having a pressing head that presses the top-seal packaging of the container at the aforementioned inspection position.

2. A seal leak inspection device for top-seal packaging as described in claim 1, The stopper is, A seal leak inspection device for top-seal packaging, characterized in that a claw is biased toward the container on the conveying conveyor, the claw is pushed back in the opposite direction of biasing by the container during transport, and at the inspection position after the container has passed, the claw protrudes in the biasing direction and contacts the rear of the container.

3. A seal leak inspection device for top-seal packaging according to claim 2, The seal leak inspection device for top-seal packaging is characterized in that the pressing head is equipped with a spring that presses the top-seal packaging between the pressing head and a cylinder portion that moves the head up and down.

4. A seal leak inspection device for top-seal packaging as described in claim 3, A seal leak inspection device for top-seal packaging, characterized in that, at the inspection position, the cylinder of the push head extends and contacts the top-seal packaging of the container, the spring contracts and then the extension of the cylinder stops, and the amount of extension of the spring after a predetermined time has elapsed is measured to determine whether or not there is a seal leak.

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