JP3255042U - Vacuum packaging device bag opening shaping and sealing mechanism - Google Patents

Abstract

[Problem] To provide a bag opening shaping and sealing mechanism for a vacuum packaging device that seals the opening of a packaging bag having flexible rigidity without wrinkles.
[Solution] The bag opening shaping and sealing mechanism of the vacuum packaging device flattens the opening of the packaging bag 1, which has been transported horizontally by a slat conveyor to the vacuum sealing position, using an expansion bar 2. While maintaining this flattened state, the left and right side edge sealing portions 3 of the opening are pressed with an upper gripper 4. After removing the expansion bar 2, the stretching member 7 of the pressing member 5 is crushed and spread to the left and right to create tension, maintaining the flattened state, and then the sealing bar 8 is used to vacuum seal it. As a result, the opening of the packaging bag 1 is reliably stretched into a flattened state and sealed without wrinkles.
[Selection Diagram] Figure 2

Description

This invention relates to a bag opening shaping and sealing mechanism for a vacuum packaging device that flattens the left and right side edges of the opening of a flexible yet rigid packaging bag by pressing and pulling them laterally, and then sealing the opening in this flattened state.

Conventionally, when attempting to seal the opening of a thin, flimsy plastic bag after filling it with the contents to be packaged, it was extremely difficult to achieve a wrinkle-free seal due to the bag's softness and lack of rigidity. Therefore, a "packaging method using bags" that enables the wrinkle-free sealing of the opening of a thin plastic bag filled with the contents is known (see Patent Document 1).

This known technology is a "packaging method using bags" in which a bag filled with the contents to be packaged is placed horizontally on a conveyor belt, air is blown from above onto the opening of the bag to flatten the opening relative to the conveyor belt, two expansion bars are inserted into the opened bag and spread horizontally to widen the bag's opening, and the widened opening of the bag is then sealed by sandwiching it from above and below. With this packaging method, even extremely thin and flimsy plastic bags can be reliably opened, and the opening of the bag can be reliably flattened by the expansion bars inserted into the opening, ensuring a seal without wrinkles.

The applicant has developed a bag opening shaping and sealing device to prevent sealing defects and wrinkles in flexible rigid packaging bags. This device expands the opening of a flexible rigid packaging bag with an expansion bar, while simultaneously clamping the left and right opening edges with upper and lower grippers and pulling them laterally to flatten them, and then sealing the flattened opening by clamping it from above and below (see Patent Document 2).
This known technology is a bag opening shaping and sealing device that transports a packaging bag horizontally by a slat conveyor to a sealing position, pre-flattens the opening of the bag with left and right expanding bars, grips the left and right side edges of the opening with upper and lower grippers while it is in this pre-flattened state, removes the expanding bars, spreads the upper and lower grippers to the left and right to completely flatten the bag, and then seals it with a sealing bar.
However, this conventional bag opening shaping and sealing device had the drawback of not being usable in vacuum packaging devices for foods and other items used for long-term storage. Therefore, this invention improves the bag opening shaping and sealing mechanism of vacuum packaging devices.

Patent No. 3098897 Japanese Patent Publication No. 2021-187518

This invention aims to provide a bag opening shaping and sealing mechanism for a vacuum packaging device that uses a pressing member and a sealing base of an upper gripper to press the left and right side edges of the opening of a flexible yet rigid packaging bag, compressing and moving the extendable member of the pressing member from side to side to flatten it, and then sealing the opening in this flattened state.

The vacuum packaging apparatus bag opening shaping and sealing mechanism of this invention comprises: a feeding device that transports packaging bags filled with the contents to be packaged in a horizontal position on a slat conveyor; an expanding bar device that inserts an expanding bar into the opening of the packaging bag at a vacuum sealing position along the feeding device and expands the opening laterally to flatten it; a flattening device that presses the left and right side edge sealing portions of the opening of the packaging bag, which has been flattened by the expanding bar device, with a sealing support and an upper gripper's pressing members, crushing the expandable member of the pressing member and expanding it laterally to flatten it by tension; and a sealing device that seals the opening of the packaging bag, which has been flattened by the tension of the expandable member, by sandwiching it from above and below with a sealing bar and a sealing support.

The vacuum packaging apparatus bag opening shaping and sealing mechanism of this invention flattens the opening of a packaging bag that has been transported horizontally at the vacuum sealing position in the loading and supplying device using an expansion bar. While maintaining this flattened state, the pressing member of the upper gripper and the sealing support base press the left and right side edges of the opening of the packaging bag. After withdrawing the expansion bar, the extension member of the pressing member is crushed and spread to the left and right, and the bag is sealed by the sealing bar and sealing support base while maintaining the flattened state due to tension. As a result, the opening of the packaging bag is reliably stretched to a flattened state and sealed without wrinkles.

This is a perspective view of a packaging bag that has been transferred to the vacuum sealing position of the bag opening shaping and sealing mechanism of the vacuum packaging device of the present invention. This is an enlarged perspective view of a packaging bag in a flattened state due to the expansion bar of the bag opening shaping and sealing mechanism of the vacuum packaging device of the present invention. This is a front view of the vacuum packaging device's bag opening shaping and sealing mechanism, showing the left and right side edges of the bag opening being pressed down by the sealing support and the extendable member of the upper gripper. This is a front view of the upper gripper of the bag opening shaping and sealing mechanism of the vacuum packaging device of the present invention, showing the state in which the expandable member is pushed out to the left and right and flattened by tension. This is a magnified longitudinal cross-sectional view of the upper gripper. This is a plan view of a three-sided sealed packaging bag.

An embodiment of the bag opening shaping and sealing mechanism of the vacuum packaging apparatus of the present invention will be described below based on the attached drawings.
As shown in the perspective view of Figure 1, the bag opening shaping and sealing mechanism of the vacuum packaging apparatus of the present invention comprises: a loading and supplying device that transports a packaging bag 1 filled with the contents to be packaged in a horizontal position on a slat conveyor (not shown); an expanding bar device that expands the opening of the packaging bag 1 laterally with an expanding bar 2 at a vacuum sealing position along the loading and supplying device to flatten it; a flattening shaping device that presses the left and right side edge sealing portions 3 of the opening of the packaging bag 1, which has been flattened by the expanding bar device, with a pressing member 5 and a sealing base 6 of an upper gripper 4, and crushes the extension member 7 (see Figures 3 and 4) of the pressing member 5 to push it out to the left and right, flattening it by tension; and a sealing device that seals the opening of the packaging bag 1, which has been flattened by the tension of the extension member 7 of the pressing member 5, by sandwiching it from above and below with a sealing base 6 and a sealing bar 8.

In the case of packaged items such as simmered dishes containing seasoning liquid, the aforementioned loading and supplying device is installed with a slat conveyor (not shown) that is set horizontally and tilted at an angle of about 5° to 7° to transport the packaging bag 1 with the opening side higher and the bottom side lower.
As shown in the enlarged perspective view of Figure 2, in this embodiment, one expansion bar device is arranged to process the packaging bags 1 transported by the slat conveyor (not shown) one bag at a time, but there may be multiple rows, and the invention is not limited to this.
The expansion bar device is provided with left and right expansion bars 2 that flatten the opening of the packaging bag 1, which is opened by the air from the spray nozzle 9, by expanding it laterally. The left and right expansion bars are fixed to the left connecting rod and the right connecting rod so as to move horizontally in the left-right direction, and the left and right connecting rods are further fixed to the left block body and the right block body.
Furthermore, although not shown in the figures, the expansion bar device has left and right levers connected to the cylinder head at an angle, which are connected to the left and right block bodies. As the expansion cylinder moves forward and backward, the left and right levers move along guide rails, causing the left and right expansion bars to move left and right, thereby expanding the left and right expansion bars 2 to the left and right.
Although not shown in the diagram, the reciprocating motion of the movable cylinder mounted on the frame moves the base, causing the expansion cylinder and guide rail mounted on the base to move forward and backward, thereby moving the expansion lever 2 forward and backward towards the opening of the packaging bag 1.

As shown in Figure 1, the flattening device is installed between the loading and supplying device and the expanding bar device, and as shown in the front views of Figures 3 and 4, the entire upper gripper 4 moves up and down toward the opening of the packaging bag 1 by the main cylinder rod 10.
The upper gripper 4 has two pressing members 5 positioned opposite each other at positions corresponding to the left and right side edge sealing portions 3 of the opening of the packaging bag 1. Each pressing member 5 is paired with an extendable member 7 attached to it so as to open to the left and right.
Each of the aforementioned pressing members 5 is fixed to the upper gripper 4 via a support shaft 16 so as to swing and rotate in the left-right direction. The pressing members 5, which are connected to the upper gripper 4 at an angle, are connected and fixed to a pressing spring 11, and the spring pressure of the pressing spring 11 can be adjusted by an adjustment stop screw 12.

The expandable member 7 is formed from a cylindrical elastic silicone member and is capable of pressing the joint points 14 of the left and right side edge sealing portions 3 of the packaging bag 1 with elastic force. The distance between the joint points 14 of the packaging bag 1 in Figure 6 corresponds to the interval R in Figure 5.
As the upper gripper 4 moves downward, the pressing member 5 moves toward the seal receiving base 6, and the pressing member 5 of the upper gripper 4 and the seal receiving base 6 press down on the left and right side edge seal portions 3 of the opening of the packaging bag 1, which has been flattened by the expanding bar 2.
When the upper gripper 4 is lowered further, the extension member 7 of the pressing member 5 is crushed and spread out to the left and right, and the tension force flattens the opening of the packaging bag 1.

As shown in Figure 1, the sealing device is provided between the upper gripper 4 and the expansion bar 2. The sealing base 6 has a fluororesin coating (Teflon® coating) on its surface to make it slippery, and the sealing bar 8 consists of a heating rod member that moves up and down by a subordinate cylinder rod 13. Further descent of the upper gripper 4 causes the expansion member 7 of the pressing member 5 to compress and tense, flattening the opening of the packaging bag 1. This opening is then sandwiched and sealed between the sealing base 6 and the sealing bar 8.

Next, the operation of the bag opening shaping and sealing mechanism of the vacuum packaging apparatus of the present invention will be described below based on the attached drawings.
As shown in Figure 1, when the packaging bag 1 filled with the contents is transported on an inclined slat conveyor to the vacuum sealing position and stops, the closed expansion bar 4 moves forward into the opening of the packaging bag 1, which has been opened by air from the spray nozzle 9, and is inserted into the opening of the packaging bag 1, expanding the opening in the left and right directions. At this time, the expansion bar 2 moves to the left and right side edge sealing portions 3 of the opening of the packaging bag 1 and expands to a flattened state.

When the expansion bar 2 moves to the left and right side edge sealing portions 3 of the opening of the packaging bag 1 and expands to a flattened state, as shown in Figure 3, the upper gripper 4 is lowered and the left and right side edge sealing portions 3 of the packaging bag 1 are pressed by the sealing support 6 and the expanding member 7 of the pressing member 5, resulting in a flattened state with a gap P. At that time, the expanding member 7 is pressing the joint points 14 shown in Figure 6 of the left and right side edge sealing portions 3 of the three-sided sealed packaging bag 1.
After removing the expansion bar 2, the vacuum chamber 14 is lowered to form a vacuum-sealed space, and while the pressing member 5 of the upper gripper 4 is under tension by pressing the left and right side edge sealing portions 3 of the packaging bag 1, the pressing member 5 is further pushed down to crush the extension member 7 and move it horizontally in the left and right directions, flattening the opening of the packaging bag 1 to a spacing Q.
When negative pressure is generated in the vacuum chamber 15, the air inside the packaging bag 1 is taut and flattened, and the tension in the opening of the packaging bag 1 is released against the pressing force of the pressing member 5, creating a gap for air circulation at the opening and allowing the air to be exhausted.
Then, the opening of the flattened packaging bag 1, which is held in tension by the extension member 7, is sealed by sandwiching it from above and below with the sealing base 6 and the sealing bar 8. Once sealing is complete, the vacuum chamber 14 moves upward, and the vacuum packaging operation is completed.

In this way, the opening of the packaging bag 1, which has been transported in a horizontal position, is flattened by the expansion bar 2. While maintaining this flattened state, the left and right side edge sealing portions 3 of the opening are pressed and expanded to the left and right with the upper gripper 4, and then vacuum-sealed with the sealing bar 8. Therefore, the opening of the packaging bag 1 is reliably stretched to a flattened state and sealed without wrinkles.

1 Packaging bag 2 Expanding bar 3 Left and right side edge sealing parts 4 Upper gripper 5 Pressing member 6 Seal receiving base 7 Extending member 8 Seal bar 9 Injection nozzle 10 Main cylinder rod 11 Pressing spring 12 Adjustment set screw 13 Subordinate cylinder rod 14 Joint point 15 Vacuum chamber 16 Support shaft

Claims (4)

A vacuum packaging apparatus bag opening shaping and sealing mechanism comprising: a feeding device that transports packaging bags filled with the contents to be packaged horizontally on a slat conveyor; an expanding bar device that inserts an expanding bar into the opening of the packaging bag at a vacuum sealing position along the feeding device and expands the opening laterally to flatten it; a flattening device that presses the left and right side edge sealing portions of the opening of the packaging bag, which has been flattened by the expanding bar device, with a sealing support and an upper gripper's pressing members, crushing the expandable member of the pressing member and expanding it laterally to flatten it by tension; and a sealing device that seals the opening of the packaging bag, which has been flattened by the tension of the expandable member, by sandwiching it from above and below with a sealing bar and a sealing support. The flattening device is provided between the feeding device and the expanding bar device, and the upper gripper has pressing members positioned opposite each other at positions corresponding to the left and right side edge sealing portions of the opening of the packaging bag, and each pressing member is a pair that opens to the left and right together with an expandable member attached to the pressing member, characterized in that it is a bag opening shaping and sealing mechanism for a vacuum packaging apparatus according to claim 1. The pressing member is fixed to the upper gripper via a support shaft so as to pivot and rotate in the left-right direction, and the pressing member, which is pivotably connected to the upper gripper at an angle, is connected and fixed to a pressing spring, and the spring pressure of the pressing spring can be adjusted by an adjustment stop screw, characterized in that the bag opening shaping and sealing mechanism of the vacuum packaging apparatus according to claim 2. The bag opening shaping and sealing mechanism of the vacuum packaging apparatus according to claim 2, characterized in that the pressing member moves toward the sealing base as the upper gripper descends, pressing the left and right side edge sealing portions of the opening of the packaging bag, which has been flattened by the expanding bar, with the pressing member of the upper gripper and the sealing base, and when the upper gripper is further descended, the expandable member of the pressing member is crushed and spread out to the left and right, and the tension force flattens the opening of the packaging bag.