Bag opening device and packaging machine equipped therewith

Abstract

To provide a bag opening device which allows a packaging bag to be further reliably opened by improving adhesion between front and back surfaces of the packaging bag and a pair of suction cups, thereby suppressing the occurrence of a suction error, and a packaging machine equipped with the same.SOLUTION: A bag opening device 20 has: a pair of suction cups 22 and 23 for opening a bag mouth which are disposed so as to face front and back surface sides a and b in the vicinity of the bag mouth of a packaging bag H filled with an object-to-be-packaged, respectively; and a suction mechanism 24 for sucking the front and back surfaces a and b in the vicinity of the bag mouth of the packaging bag H by the pair of suction cups 22 and 23 for opening the bag mouth, respectively. The pair of suction cups 22 and 23 for opening the bag mouth can be vibrated by a vibration mechanism 25 when sucking the packaging bag H.SELECTED DRAWING: Figure 2

Description

Technical Field

[0001] The present invention relates to a bag opening device for opening a packaging bag and a packaging machine provided with the same.

Background Art

[0002] Conventionally, a bag opening device that sucks and opens a packaging bag from the front and back surfaces by a pair of suction cups and a packaging machine provided with the same have been widely used (for example, Japanese Patent Application Laid-Open No. 2013-91498 or Japanese Patent Application Laid-Open No. 2015-182770).

[0003] However, when the positional relationship between the packaging bag and the suction cup is poor (for example, when a punch hole or the like exists in the suction part of the packaging bag), when the packaging bag has irregularities (for example, when film wrinkles or the chuck of a chuck bag exists in the suction part of the packaging bag), or when the packaging bag is soft (for example, when the packaging bag is formed of a thin film or the like), even if the pair of suction cups reach the suction parts of the packaging bag from the front and back surfaces, the adhesion with the packaging bag is low, the vacuum pressure does not increase, and suction failure may occur and the opening may not be possible.

Prior Art Documents

Patent Documents

[0004]

Patent Document 1

Patent Document 2

Summary of the Invention

Problems to be Solved by the Invention

[0005] Therefore, an object of the present invention is to provide a bag opening device that improves the adhesion between the front and back surfaces of a packaging bag and a pair of suction cups, suppresses the occurrence of suction failure, and can open more reliably, and a packaging machine provided with the same.

Means for Solving the Problems

[0006] The solution to the above problem comprises a pair of suction cups for opening the bag opening, each positioned opposite the front and back surfaces near the opening of the packaging bag into which the packaged goods are filled, and a suction mechanism for adsorbing the front and back surfaces near the opening of the packaging bag by the pair of suction cups, wherein the pair of suction cups for opening the bag opening are configured to vibrate by a vibration mechanism when the packaging bag is adsorbed. The vibration mechanism has a first vacuum source and a second vacuum source set to different vacuum pressures, and generates pulsation by repeatedly switching the second vacuum source ON and OFF when suction is generated by the first vacuum source, causing the pair of suction cups for opening the bag opening to vibrate. A bag opening device characterized by the above (Claim 1).

[0007] Preferably, the vibration mechanism comprises a first vacuum pump as the first vacuum source, a second vacuum pump as the second vacuum source, a first vacuum solenoid valve for opening and closing the first vacuum pump, and a second vacuum solenoid valve for opening and closing the second vacuum pump, and generates pulsation by opening the first vacuum solenoid valve and drawing in with the first vacuum pump, and repeatedly opening and closing with the second vacuum solenoid valve while drawing in with the second vacuum pump, thereby vibrating the pair of suction cups for opening the bag opening (Claim) 2 ).

[0008] Furthermore, a solution to the above problems includes a pair of suction cups for opening the bag opening, each positioned opposite the front and back surfaces near the opening of the packaging bag into which the packaged goods are filled, and a suction mechanism for adsorbing the front and back surfaces near the opening of the packaging bag by the pair of suction cups, wherein the pair of suction cups for opening the bag opening are configured to vibrate by a vibration mechanism when the packaging bag is adsorbed. The vibration mechanism comprises a vacuum source and an atmospheric communication section that communicates with the atmosphere, and the opening and closing of the atmospheric communication section is repeatedly performed when suction is performed by the vacuum source to generate pulsation and vibrate the pair of suction cups for opening the bag opening, as described in claim 1 (Claim 3).

[0009] Furthermore, a packaging machine that solves the above problems is characterized by having a bag opening device comprising: a pair of suction cups for opening the bag opening, which are arranged opposite each other on the front and back sides near the opening of the packaging bag in which the contents to be packaged are filled; and a suction mechanism for adsorbing the front and back sides near the opening of the packaging bag by the pair of suction cups for opening the bag opening, wherein the pair of suction cups for opening the bag opening are configured to vibrate by a vibration mechanism when the packaging bag is adsorbed, and the vibration mechanism has a first vacuum source and a second vacuum source set to different vacuum pressures, and generates pulsation by repeatedly turning the second vacuum source ON and OFF when suction is performed by the first vacuum source, thereby vibrating the pair of suction cups for opening the bag opening (Claim 4).

[0010] Furthermore, a packaging machine that solves the above problems is characterized by having a bag opening device comprising: a pair of suction cups for opening the bag opening, each positioned opposite the front and back surfaces near the opening of the packaging bag in which the contents are filled; and a suction mechanism for adsorbing the front and back surfaces near the opening of the packaging bag by the pair of suction cups for opening the bag opening, wherein the pair of suction cups for opening the bag opening are configured to vibrate by a vibration mechanism when the packaging bag is adsorbed, and the vibration mechanism comprises a vacuum source and an atmospheric communication section that communicates with the atmosphere, and generates pulsation by repeatedly opening and closing the atmospheric communication section when suction is performed by the vacuum source, thereby vibrating the pair of suction cups for opening the bag opening (Claim 5). . [Effects of the Invention]

[0011] Claim 1 or 3 The bag opening device described above improves the adhesion between the front and back surfaces near the opening of the packaging bag and the pair of suction cups for opening the bag opening, thereby suppressing the occurrence of suction errors and enabling more reliable opening of the bag opening. Furthermore, the vibration mechanism can be constructed with a simple structure. Claim 4 or 5According to the packaging machine described, the adhesion between the front and back surfaces near the opening of the packaging bag and the pair of suction cups for opening the bag opening is improved, suppressing the occurrence of suction errors and enabling the bag opening to be opened more reliably, while also allowing the vibration mechanism to be constructed with a simple structure. [Brief explanation of the drawing]

[0012] [Figure 1] This is a schematic plan view of one embodiment of a packaging machine equipped with the bag opening device of the present invention. [Figure 2] This is a schematic perspective view illustrating one embodiment of the bag opening device of the present invention. [Figure 3] Figure 2 is a schematic perspective view illustrating the bag opening device. (a) shows the bag opening and bottom interior closed, with the pair of suction cups for opening the bag opening and the pair of suction cups for opening the bottom in their closest positions. (b) is an explanatory diagram showing the bag opening and bottom interior open, with the pair of suction cups for opening the bag opening and the pair of suction cups for opening the bottom in their intermediate positions. [Figure 4] This is a schematic perspective view illustrating another embodiment of the bag opening device of the present invention. [Figure 5] This is a schematic perspective view illustrating another embodiment of the bag opening device of the present invention. [Modes for carrying out the invention]

[0013] In this invention, a bag opening device 20 and a packaging machine P equipped therewith are realized, which have a pair of suction cups 22 and 23 for opening the bag opening, which are positioned opposite each other on the front and back surfaces a and b near the opening of the packaging bag H, respectively, and a suction mechanism 24 for adsorbing the front and back surfaces a and b near the opening of the packaging bag H by the pair of suction cups 22 and 23, respectively, and the pair of suction cups 22 and 23 are configured to vibrate by a vibration mechanism 25 when the packaging bag H is adsorbed, thereby improving the adhesion between the front and back surfaces a and b near the opening of the packaging bag H and the pair of suction cups 22 and 23, suppressing the occurrence of adsorption errors and enabling a more reliable opening of the bag opening. [Examples]

[0014] The packaging machine equipped with the bag opening device of the present invention will be described using an embodiment shown in FIGS. 1 to 3. The packaging machine P of this embodiment has a pair of suction cups 22 and 23 for opening the bag mouth, which are respectively arranged opposite to the front and back surfaces a and b near the bag mouth of the packaging bag H for filling the object to be packaged, and a suction mechanism 24 for sucking the front and back surfaces a and b near the bag mouth of the packaging bag H by the pair of suction cups 22 and 23 for opening the bag mouth. The pair of suction cups 22 and 23 for opening the bag mouth are provided with a bag opening device 20 configured to be vibratable by a vibration mechanism 25 when the packaging bag H is sucked. Hereinafter, each component will be described in detail in sequence.

[0015] As shown in FIG. 1, the packaging machine P of this embodiment intermittently stops and moves a moving body 10 having a grip pair g to a plurality of stations, and fills the packaging bag H supported in a vertical posture by the grip pair g with the object to be packaged and seals the bag mouth. The packaging machine P is provided with a bag opening device 20 at a bag opening station 4 that performs a bag opening process for opening the packaging bag H.

[0016] As shown in FIG. 2, the bag opening device 20 of this embodiment has a pair of suction cups 22 and 23 for opening the bag mouth, which are respectively arranged opposite to the front and back surfaces of the packaging bag for filling the object to be packaged H and a position control motor 26 for moving the pair of suction cups 22 and 23 for opening the bag mouth between a standby position separated from the packaging bag H, an intermediate position which is the opening holding position of the packaging bag H, and a closest position for sucking the front and back surfaces of the packaging bag H respectively.

[0017] The packaging machine P in this embodiment is a device that opens the opening of a packaging bag H, fills it with the contents to be packaged, and seals it. As shown in Figure 1, the device performs a total of 10 steps at each station: a bag supply step (bag supply station 1) for supplying packaging bags H to the packaging machine, a printing step (printing station 2) for printing the expiration date, etc., a printing inspection step (printing inspection station 3) for performing printing inspection, a bag opening step (bag opening station 4) for opening the opening and the inside of the bottom of the packaging bag, a filling step (filling station 5) for filling the contents to be packaged into the packaging bag, a pushing step (pushing station 6) for pushing the contents to be packaged, a blowing step (blowing station 7) for blowing away the contents near the opening of the bag, a top seal and air venting step (top seal station 8) for sealing the area near the opening of the bag horizontally and venting air from inside the packaging bag, a top seal cooling step (cooling station 9) for cooling the top seal, and a product discharge step (product discharge station 10) for discharging the packaging bag H containing the contents to the outside of the machine.

[0018] Although this embodiment uses a rotary-type packaging machine P, the present invention can also be applied to known linear-movement type packaging machines and truck-type packaging machines.

[0019] In this packaging machine P, as shown in Figure 1, a stand is provided on the machine base to freely support an intermittent rotating shaft 12 that extends vertically. A movable body (disc-shaped rotating body) 10 attached to the upper part of the intermittent rotating shaft 12 is provided with 10 pairs of grips g for gripping or releasing packaging bags a, which protrude radially at equal angular intervals around the intermittent rotating shaft 12. The packaging machine P is configured such that at the bag feeding station 1, packaging bags H are picked up by a bag feeding device 13, and the packaging bags H are suspended in a vertical position by pairs of grips g that move intermittently to the bag feeding station 1 in sequence.

[0020] As shown in Figure 1, the bag opening station 4, which performs the bag opening process, is equipped with a bag opening device 20. As shown in Figure 2, this bag opening device 20 has a pair of suction cups 22 and 23 for opening the bag opening, which are positioned opposite each other on the front and back sides of the packaging bag H that is filled with the packaged goods. These pair of suction cups 22 and 23 are in communication with a suction mechanism 24, which sucks the packaging bag H from the front and back sides, respectively, and moves the packaging bag H to an intermediate position, which is the opening holding position, while holding the bag opening, thereby opening the bag opening.

[0021] The reciprocating mechanism for the bag opening suction cups 22 and 23, which allows the pair of bag opening suction cups 22 and 23 to move freely between a standby position, an intermediate position, and a closest position, comprises a position control motor 26 and arms 28 and 29 connected to the pivot shaft 27 of the position control motor 26 and rotating in conjunction with the rotation of the pivot shaft 27. The pair of bag opening suction cups 22 and 23 are attached to the lower ends of the arms 28 and 29, respectively.

[0022] Suitable motors for position control include servo motors, stepping motors, and brushless motors, but in this embodiment, a servo motor is used.

[0023] The suction mechanism 24 is for adsorbing the packaging bag H using the suction cups 22 and 23 for opening the bag opening. In this embodiment, the suction mechanism 24 is composed of a first vacuum pump 30, which is the first vacuum source, as shown in Figure 2. Specifically, the suction of the suction cups 22 and 23 for opening the bag opening by the first vacuum pump 30 is controlled by the PLC (control panel) 31, which controls the first vacuum pump 30 and the first vacuum solenoid valve 32.

[0024] The vibration mechanism 25 is used to vibrate the suction cups 22 and 23 for opening the bag opening when they are attracted to the packaging bag H. As shown in Figure 2, the vibration mechanism 25 in this embodiment has a first vacuum source 30 and a second vacuum source 33 set to different vacuum pressures (vacuum levels). When the first vacuum source 30 is used for suction, the second vacuum source 33 is repeatedly switched ON and OFF at high speed (preferably 10 to 100 Hz to generate good vibration; in this embodiment, it is set to be switched ON and OFF or to open and close a solenoid valve at 30 Hz) to generate pulsation and vibrate the suction cups 22 and 23 for opening the bag opening.

[0025] Specifically, the vibration mechanism 25 of this embodiment has a first vacuum source 30 which is a first vacuum pump, a second vacuum source 33 which is a second vacuum pump, a first vacuum solenoid valve 32 which opens and closes the first vacuum pump 30, and a second vacuum solenoid valve 34 which opens and closes the second vacuum pump 33. By opening the first vacuum solenoid valve 32 and drawing air with the first vacuum pump 30 (e.g., -40kPa), and repeatedly opening and closing the second vacuum solenoid valve 34 at high speed while drawing air with the second vacuum pump 33 (e.g., -60kPa), pulsation is generated in the pipes of the two connected parts, causing the bag opening suction cups 22 and 23 to vibrate. This makes it possible to vary the vacuum pressure when the bag opening suction cups 22 and 23 adsorb the packaging bag H, thereby removing air present in the gap between the bag opening suction cups 22 and 23 and the packaging bag H to improve airtightness, and also circulating residual oxygen etc. inside the packaging bag H to improve the accuracy of measuring the gas concentration inside the packaging bag H.

[0026] First vacuum pump 30, second vacuum pump 33, first vacuum solenoid valve 32, second vacuum solenoid valve 34, and control panel for setting the vacuum pressure of the first vacuum pump 30 and second vacuum pump 33. 35 This is configured to be controlled by PLC31. Note that the vacuum source is not limited to a vacuum pump as in this embodiment; any device capable of suction may be used, such as a blower or ejector.

[0027] Furthermore, as shown in Figure 3, the bag opening device 20 of this embodiment has a pair of suction cups 22 and 23 for opening the bag opening, which are positioned opposite each other on the front and back surfaces a and b near the opening of the packaging bag H that is filled with the packaged goods, as well as a pair of suction cups 50 and 51 for opening the bottom, which are positioned opposite each other on the front and back surfaces a and b near the bottom of the packaging bag H that is filled with the packaged goods. The pair of bottom opening suction cups 50 and 51 are configured to vibrate when the packaging bag H is attached.

[0028] These pair of bottom-opening suction cups 50, 51 are provided because, for example, in the case of a self-standing bag (standing pack) with a gusset at the bottom, it is necessary to open not only the opening of the bag but also the inside of the bottom. The suction mechanism of the pair of bottom-opening suction cups 50, 51 is the suction mechanism 24 described above, and the vibration mechanism is the vibration mechanism 25 described above. These improve the adhesion between the front and back surfaces a, b near the bottom of the packaging bag H and the pair of bottom-opening suction cups 50, 51, suppressing the occurrence of suction errors and enabling more reliable opening of the inside of the bottom. 3 (a) shows the bag opening and bottom interior closed, with the pair of suction cups for opening the bag opening and the pair of suction cups for opening the bottom in their closest positions, as shown in Figure 3 (b) teeth The image shows the bag opening and bottom interior in an open state, with a pair of suction cups for opening the bag opening and a pair of suction cups for opening the bottom of the bag in an intermediate position.

[0029] Next, another embodiment of the bag opening device of the present invention shown in Figure 4 will be described. The fundamental difference between the bag opening device 40 of this embodiment and the bag opening device 20 described above lies in the configuration of the vibration mechanism; otherwise, it is the same as the bag opening device 20. Parts identical to those of the bag opening device 20 are denoted by the same reference numerals and their descriptions are omitted.

[0030] In this embodiment, the bag opening device 40 uses only a vacuum pump 41 as a vacuum source for adsorbing the packaging bag H by suction using the bag opening suction cups 22 and 23. Suction by the vacuum pump 41 is performed by controlling the vacuum pump 41 and the vacuum solenoid valve 43 with a PLC 31 (suction mechanism 42 of the bag opening device 40).

[0031] In this embodiment, the vibration mechanism 44 is a vibrator 45 provided within the main body 47 of the bag opening device 40. The vibrator 45 vibrates, causing the bag opening suction cups 22 and 23 to vibrate while being sucked by the vacuum pump 41. In this embodiment, the vibrator 45 is an air-operated rotary vibrator whose vibration is controlled by a vibration solenoid valve 46 controlled by a PLC 42. However, any vibration mechanism capable of vibrating the bag opening suction cups 22 and 23 is acceptable, and bag opening devices composed of, for example, an air-operated piston vibrator or an electric vibrator are also included in the scope of the present invention.

[0032] Furthermore, another embodiment of the bag opening device of the present invention shown in Figure 5 will be described. The fundamental difference between the bag opening device 60 of this embodiment and the bag opening device 20 described above lies in the configuration of the vibration mechanism; otherwise, it is the same as the bag opening device 20. Parts identical to those of the bag opening device 20 are denoted by the same reference numerals and their descriptions are omitted.

[0033] In this embodiment, the bag opening device 60 uses only a vacuum pump 61 as a vacuum source for sucking the bag opening suction cups 22, 23 to adsorb the packaging bag H. Suction by the vacuum pump 61 is performed by controlling the vacuum pump 61 and the vacuum solenoid valve 62 with a PLC 31 (suction mechanism 63 of the bag opening device 60).

[0034] Furthermore, the vibration mechanism 64 in this embodiment includes a suction mechanism 63 and an atmospheric communication section 65 that communicates with the atmosphere (in this embodiment, a pipe 66 with one end open to the atmosphere and a solenoid valve 67 for opening and closing the pipe 66).

[0035] Furthermore, the system is configured to generate pulsation by rapidly opening and closing the atmospheric communication section 65 when suction is performed by a vacuum source (vacuum pump 61), causing the pair of bag opening suction cups 22 and 23 to vibrate.

[0036] Thus, the bag opening device of the present invention is not limited to those that use two vacuum sources, a first vacuum source 30 and a second vacuum source 32, as described above, in order to generate pulsation using two different pressures. The present invention also includes devices such as the bag opening device 60 of this embodiment, which have one vacuum source (vacuum pump 61) and an atmospheric communication section 65, and realize different pressures using vacuum pressure and atmospheric pressure.

[0037] Furthermore, the present invention also includes a bag opening device characterized by having a pair of bottom-opening suction cups 50, 51 positioned opposite each other on the front and back surfaces a and b near the bottom of the packaging bag H into which the packaged goods are filled, and a suction mechanism 24 for adsorbing the front and back surfaces a and b near the bottom of the packaging bag H using the pair of bottom-opening suction cups 50, 51, respectively, wherein the pair of bottom-opening suction cups 50, 51 are configured to vibrate by a vibration mechanism 25 when the packaging bag H is adsorbed. In other words, a bag opening device configured to have only a mechanism for opening the bottom of the packaging bag and not a mechanism for opening the mouth of the packaging bag is also included in the scope of the present invention. This improves the adhesion between the front and back surfaces a and b near the bottom of the packaging bag H and the pair of bottom-opening suction cups 50, 51, suppresses the occurrence of adsorption errors, and allows for more reliable opening of the inside of the bottom.

[0038] Similarly, the present invention also includes a packaging machine equipped with a bag opening device that features a pair of bottom-opening suction cups 50 and 51 positioned opposite each other on the front and back surfaces a and b near the bottom of the packaging bag H into which the packaged goods are filled, and a suction mechanism 24 for adsorbing the front and back surfaces a and b near the bottom of the packaging bag H using the pair of bottom-opening suction cups 50 and 51, respectively, wherein the pair of bottom-opening suction cups 50 and 51 are configured to vibrate by a vibration mechanism 25 when the packaging bag H is adsorbed. In other words, the present invention also includes a packaging machine equipped with a bag opening device configured to have only a mechanism for opening the bottom of the packaging bag, and not a mechanism for opening the mouth of the packaging bag. This improves the adhesion between the front and back surfaces a and b near the bottom of the packaging bag H and the pair of bottom-opening suction cups 50 and 51, suppresses the occurrence of adsorption errors, and allows for more reliable opening of the inside of the bottom. [Explanation of Symbols]

[0039] P packaging machine 4 Bag Opening Station 10 Mobile Units 12 Intermittent rotation shaft 13 Bag feeding device 20 Bag opening device 22,23 Suction cup for bag mouth opening 24 Suction mechanism 25 Vibration mechanism 26 Position control motor 27 Rotary shafts 28, 29 Arms 30. First Vacuum Source (First Vacuum Pump) 31 PLC 32 First Vacuum Solenoid Valve 33. Second vacuum source (second vacuum pump) 34. Second Vacuum Solenoid Valve 35 Control Panel 40 Bag opening device 41 Vacuum pump 42 Suction mechanism 43 Vacuum Solenoid Valve 44 Vibration mechanism 45 Vibrators 46. ​​Vibrating Solenoid Valve 47 Main body 50,51 Suction cup for bottom opening 60 Bag opening device 61 Vacuum pump 62 Vacuum Solenoid Valve 63 Suction mechanism 64 Vibration mechanism 65 Atmospheric communication section 66 pipes 67 Solenoid valve H packaging bag g grip a surface b Back side

Claims

1. A pair of suction cups for opening the bag opening are positioned opposite each other on the front and back sides near the opening of the packaging bag into which the packaged goods are filled, The bag opening opening suction cups have a suction mechanism for adsorbing the front and back surfaces near the opening of the packaging bag, respectively. The pair of suction cups for opening the bag opening are configured to vibrate by a vibration mechanism when the packaging bag is attached. The aforementioned vibration mechanism has a first vacuum source and a second vacuum source set to different vacuum pressures, and the bag opening device is characterized in that it generates pulsation by repeatedly turning the second vacuum source ON and OFF when suction is performed by the first vacuum source, thereby vibrating the pair of suction cups for opening the bag opening.

2. The vibration mechanism comprises a first vacuum pump as the first vacuum source, a second vacuum pump as the second vacuum source, a first vacuum solenoid valve for opening and closing the first vacuum pump, and a second vacuum solenoid valve for opening and closing the second vacuum pump, wherein pulsation is generated by opening the first vacuum solenoid valve and drawing in with the first vacuum pump, and repeatedly opening and closing with the second vacuum solenoid valve while drawing in with the second vacuum pump, thereby vibrating the pair of suction cups for opening the bag opening, as described in claim 1.

3. A pair of suction cups for opening the bag opening are arranged opposite each other on the front and back sides near the opening of the packaging bag in which the packaged goods are filled, The bag opening opening suction cups have a suction mechanism for adsorbing the front and back surfaces near the opening of the packaging bag, respectively. The pair of suction cups for opening the bag opening are configured to vibrate by a vibration mechanism when the packaging bag is attached. The bag opening device according to claim 1, wherein the vibration mechanism comprises a vacuum source and an atmospheric communication section that communicates with the atmosphere, and generates pulsation by repeatedly opening and closing the atmospheric communication section when suction is performed by the vacuum source, thereby vibrating the pair of suction cups for opening the bag opening.

4. A pair of suction cups for opening the bag opening are arranged opposite each other on the front and back sides near the opening of the packaging bag in which the contents are filled, and a suction mechanism is provided for adsorbing the front and back sides near the opening of the packaging bag by the pair of suction cups for opening the bag opening, wherein the pair of suction cups for opening the bag opening are configured to vibrate by a vibration mechanism when the packaging bag is adsorbed. The packaging machine is characterized in that the vibration mechanism has a first vacuum source and a second vacuum source set to different vacuum pressures, and the bag opening device generates pulsation by repeatedly turning the second vacuum source ON and OFF when the first vacuum source is used for suction, thereby vibrating the pair of suction cups for opening the bag opening.

5. A pair of suction cups for opening the bag opening are arranged opposite each other on the front and back sides near the opening of the packaging bag in which the contents are filled, and a suction mechanism is provided for adsorbing the front and back sides near the opening of the packaging bag by the pair of suction cups for opening the bag opening, wherein the pair of suction cups for opening the bag opening are configured to vibrate by a vibration mechanism when the packaging bag is adsorbed. The packaging machine is characterized in that the vibration mechanism comprises a vacuum source and an atmospheric communication section that communicates with the atmosphere, and the bag opening device generates pulsation by repeatedly opening and closing the atmospheric communication section when suction is performed by the vacuum source, thereby vibrating the pair of suction cups for opening the bag opening.

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