Air tightness detection device for packaging plastic bag

Abstract

The invention relates to the technical field of plastic bag airtightness testing, in particular to an airtightness detection device for a packaging plastic bag. Comprising a fixing frame, the fixing frame is provided with a detection shell, the fixing frame is provided with an electric rotating shaft, the electric rotating shaft of the fixing frame is provided with a rotating frame, a supporting plate is slidably connected into the detection shell, a transmission rod is fixedly connected to the upper side of the supporting plate, and a supporting shell is fixedly connected to the lower side of the supporting plate; the supporting shell is provided with symmetrically-distributed driving pieces, the driving pieces are fixedly connected with two symmetrically-distributed elastic telescopic rods, the telescopic ends of the elastic telescopic rods are provided with electric rotating shafts, and the electric rotating shafts are fixedly connected with L-shaped frames. The electric rotating shaft on the elastic telescopic rod drives the L-shaped frame to rotate, so that the L-shaped frame turns over a sealing edge in the middle of a plastic bag, the sealing edge in the middle of the plastic bag is changed into a vertical state from a horizontal state, and a worker can conveniently observe the damage condition of the position of the plastic bag in the detection process.

Description

Technical Field

[0001] The invention relates to the technical field of plastic bag sealing test, and in particular to an airtightness detection device for packaging plastic bags. Background Art

[0002] Packaging plastic bags are a type of plastic product commonly used in the fields of food and medicine. They are used to protect food and medicines and prevent them from being contaminated during transportation. In the food production process, the packaged products need to be tested for airtightness to ensure the sealing effect of the food packaging plastic bags on the internal items. Currently, the common airtightness detection devices on the market mainly test the sealing performance of packaging plastic bags by simulating different environmental conditions, such as the pressure difference method, the gas tracking method, etc. These methods can detect whether there are leaks in the packaging plastic bags to a certain extent. They usually rely on observing the pressure changes caused by gas leakage or the presence of tracer gas to judge the airtightness.

[0003] However, the existing air tightness detection device has a significant disadvantage in actual operation: it is unable to effectively flip the sealing edge in the middle of the packaging plastic bag. As a result, when a leak occurs in this area of ​​the packaging plastic bag, the leaked gas will flow along the sealing edge of the packaging plastic bag to other locations instead of being directly captured by the detection equipment. This will cause the data obtained by the inspectors to be inaccurate, making it difficult to accurately locate the source of the leak, affecting the accuracy and reliability of the final test results, and further affecting the subsequent adjustments to the production of packaging plastic bags. Summary of the invention

[0004] The present invention provides an air tightness detection device for packaging plastic bags, so as to overcome the disadvantage that the existing detection device cannot flip the sealing edge in the middle of the plastic bag, causing the gas leaked here to be easily discharged from other positions, resulting in reduced accuracy of the detection result.

[0005] The technical solution of the present invention is: an airtightness detection device for packaging plastic bags, comprising a fixed frame, the fixed frame is provided with a detection shell, the detection shell is connected with a vacuum pump through a hose, the fixed frame is provided with an electric rotating shaft, the electric rotating shaft of the fixed frame is provided with a rotating frame, the rotating frame is provided with a sealing cover, the sealing cover is used to block the detection shell, a support plate is slidably connected in the detection shell, a first spring is provided between the support plate and the detection shell, a transmission rod is fixedly connected to the upper side of the support plate, the transmission rod is located on the moving path of the sealing cover, the support plate is fixedly connected to the lower side of the support plate, the support shell is provided with a symmetrically distributed driving member, the driving member is fixedly connected with two symmetrically distributed elastic telescopic rods, the telescopic end of the elastic telescopic rod is provided with an electric rotating shaft, the electric rotating shaft is fixedly connected with an L-shaped frame, the L-shaped frame is used to flip the sealing edge in the middle of the plastic bag, and the L-shaped frame is provided with a separation mechanism for driving the sealing edge in the middle of the plastic bag to rotate.

[0006] As a preferred embodiment, the separation mechanism includes a rotating plate, which is rotatably connected to the adjacent L-shaped frame, a torsion spring is fixedly connected between the rotating plate and the L-shaped frame, the L-shaped frame is rotatably connected to a limit plate, a pull rope is fixedly connected between the limit plate and the rotating plate, and the telescopic end of the elastic telescopic rod is located on the rotation path of the limit plate.

[0007] As a preference, the angle between the rotating plate, a portion of the elastic telescopic rod and the L-shaped frame is equal to the maximum rotation angle thereof.

[0008] As a preference, an elastic plate is fixedly connected between the rotating plate and the adjacent L-shaped frame, and the elastic plate is used to support the sealing edge of the plastic bag.

[0009] As a preferred embodiment, it also includes a limiting component, which is arranged on the supporting shell, and is used to limit the height of the L-shaped frame. The limiting component includes limiting rods whose number is the same as the number of the elastic telescopic rods, and the limiting rods are fixed to the telescopic parts of the adjacent elastic telescopic rods. The supporting shell is fixed with two symmetrically distributed guide strips, and the guide strips are used to limit the height of the adjacent limiting rods.

[0010] As a preferred embodiment, it also includes symmetrically distributed adjustment components, which are all arranged on the support plate, and the adjustment components are used to adjust the position of the plastic bag. The adjustment components include: a positioning frame, which is slidably connected to the support plate, and the positioning frame is fixed with a positioning plate, the positioning plate is slidably connected to the support plate, and the upper part of the transmission rod is higher than the upper part of the positioning plate, and the positioning plate is used to adjust the position of the plastic bag, a second spring is fixed between the positioning frame and the support plate, and the detection shell is fixed with a vibration plate, and a plurality of protrusions are arranged on the side of the vibration plate adjacent to the positioning plate, and the protrusions on the vibration plate are used to squeeze the positioning frame, and two symmetrically distributed fixing components are arranged on the support plate, and the fixing components are used to fix adjacent sealing edges of the plastic bag.

[0011] As a preference, the height of the largest protrusion between the vibration plate and the support plate is greater than the heights of other protrusions, so that the positioning plate can limit the position of the plastic bag.

[0012] Preferably, the upper portion of the positioning plate is arc-shaped, and the upper portion of the positioning plate is deflected toward the center direction of the supporting plate.

[0013] As a preferred embodiment, it also includes a power component, which is arranged on the rotating frame, and the power component is used to squeeze the plastic bag. The power component includes: an electric push rod, which is fixed to the rotating frame, and the telescopic end of the electric push rod is slidably connected to the rotating frame, and the telescopic end of the electric push rod is fixed with a connecting pipe, and the connecting pipe is externally connected to an air pump through the connecting pipe, and the connecting pipe is slidably connected to the sealing cover, and the connecting pipe is slidably connected and connected to a suction cup, and the suction cup is used to fix the plastic bag.

[0014] As a preference, a fourth spring is fixedly connected between the connecting pipe and the sealing cover, and the connecting pipe is fixedly connected to an extrusion frame, and the extrusion frame evenly squeezes the plastic bag through the suction cup.

[0015] Beneficial effects: 1. When the present invention performs air tightness test on plastic bags, the electric rotating shaft on the elastic telescopic rod drives the L-shaped frame to rotate, so that the L-shaped frame flips the sealing edge in the middle of the plastic bag, so that the sealing edge in the middle of the plastic bag is changed from a horizontal state to a vertical state, thereby facilitating the staff to observe the damage of the plastic bag at this point during the test, thereby improving the accuracy of the test data.

[0016] 2. In the process of fixing and flipping the middle sealed edge of the plastic bag, the present invention rotates the rotating plate by pulling the rope, so that the rotating plate gradually squeezes the edge of the middle sealed edge of the plastic bag, increases the fixed position of the middle sealed edge of the plastic bag, and thus improves the flipping effect of the middle sealed edge of the plastic bag.

[0017] 3. In the process of flipping the sealed edge in the middle of the plastic bag, the positioning plate is used to intermittently squeeze the edge of the plastic bag, driving the plastic bag to shake and adjust its position and angle, so that the plastic bag is located in the middle of the support plate, ensuring that the sealed edge in the middle of the plastic bag can contact the L-shaped frame and be flipped. BRIEF DESCRIPTION OF THE DRAWINGS

[0018] Figure 1 It is a schematic diagram of the three-dimensional structure of the present invention; Figure 2 It is a schematic diagram of the three-dimensional structure of the detection shell, the rotating frame and the sealing cover of the present invention; Figure 3 It is a schematic diagram of the three-dimensional structure of the positioning frame, the positioning plate and the connecting pipe of the present invention; Figure 4 It is a schematic diagram of the three-dimensional structure of the transmission rod, the driving member and the elastic telescopic rod of the present invention; Figure 5 It is a three-dimensional structural schematic diagram of the L-shaped frame, the limiting rod and the guide strip of the present invention; Figure 6 It is a schematic diagram of the three-dimensional structure of the rotating plate, the limiting plate and the pull rope of the present invention; Figure 7 It is a three-dimensional structural cross-sectional view of the L-shaped frame, the rotating plate and the elastic plate of the present invention; Figure 8 It is a schematic diagram of the three-dimensional structure of the support plate, the positioning frame and the vibration plate of the present invention; Fig. 9 It is a schematic diagram of the three-dimensional structure of the positioning frame, the positioning plate and the second spring of the present invention; Fig.10 It is a three-dimensional structural cross-sectional view of the sealing cover, the connecting pipe and the extrusion frame of the present invention.

[0019] Marked in the figure: 1-fixed frame, 2-detection shell, 3-rotating frame, 4-sealing cover, 5-support plate, 501-first spring, 6-transmission rod, 7-support shell, 8-driving member, 9-elastic telescopic rod, 10-L-shaped frame, 11-rotating plate, 12-torsion spring, 13-limiting plate, 14-pull rope, 15-elastic plate, 16-limiting rod, 17-guide strip, 18-positioning frame, 19-positioning plate, 20-second spring, 21-vibration plate, 30-electric push rod, 31-connecting pipe, 32-suction cup, 33-fourth spring, 34-extrusion frame. DETAILED DESCRIPTION

[0020] The present invention will be further described below in conjunction with the embodiments shown in the accompanying drawings.

[0021] An airtightness detection device for packaging plastic bags, such as Figure 1-Figure 7As shown, it includes a fixed frame 1, the fixed frame 1 is provided with a detection shell 2, the detection shell 2 is connected to the vacuum pump through a hose, the fixed frame 1 is provided with an electric rotating shaft, the electric rotating shaft of the fixed frame 1 is provided with a rotating frame 3, the rotating frame 3 is provided with a sealing cover 4, the sealing cover 4 is used to block the detection shell 2, a support plate 5 is slidably connected in the detection shell 2, a first spring 501 is provided between the support plate 5 and the detection shell 2, a transmission rod 6 is fixedly connected to the upper side of the support plate 5, the transmission rod 6 is located on the moving path of the sealing cover 4, a support shell 7 is fixedly connected to the lower side of the support plate 5, the support shell 7 is provided with a symmetrically distributed driving member 8, the driving member 8 is fixedly connected with two symmetrically distributed elastic telescopic rods 9, the telescopic end of the elastic telescopic rod 9 is provided with an electric rotating shaft, the electric rotating shaft is fixedly connected with an L-shaped frame 10, the L-shaped frame 10 is used to flip the sealing edge in the middle of the plastic bag, and the L-shaped frame 10 is provided with a separation mechanism for driving the sealing edge in the middle of the plastic bag to rotate.

[0022] The above scheme provides a method for standing up the sealing edge in the middle of the plastic bag when there is a leak in the packaging plastic bag, so as to facilitate observation of the leakage position of the plastic bag; a conveyor belt is provided in the device, and the conveyor belt is an existing device, and the specific structure will not be described in detail. The conveyor belt is used to transport food packaging plastic bags (hereinafter referred to as plastic bags), and the vacuum pump is used to extract the gas in the detection shell 2 to expand the plastic bag and create a pressure difference between the inside and the outside. The detection shell 2 is used to hold water, and the water is used to make the gas leaked from the plastic bag form bubbles for easy observation. In this embodiment, an electric telescopic rod is provided on the rotating frame 3, and the telescopic end of the electric telescopic rod drives the sealing cover 4 to move up and down, and the electric rotating shaft on the fixed frame 1 is used to drive the sealing cover 4 to rotate through the rotating frame 3. Initially, the axis of the sealing cover 4 is misaligned with the axis of the detection shell 2, so that the staff can put the plastic bag into the detection shell 2. An air pressure sensor is provided on the sealing cover 4 to detect the change of air pressure in the detection shell 2, so as to determine whether the plastic bag is leaking, and the support plate 5 is provided with a plurality of flow holes. , used to allow water to pass through, the detection shell 2, the support plate 5 and the support shell 7 are all transparent, which is used to facilitate the staff to observe the position where the bubbles in the plastic bag are discharged. A cross plate is arranged in the detection shell 2, and the first spring 501 is located between the cross plate of the detection shell 2 and the support plate 5. The first spring 501 is used to push the support plate 5 to move upward and reset. The height of the transmission rod 6 is greater than the height of the plastic bag, so that the sealing cover 4 cannot squeeze the plastic bag when pushing the transmission rod 6. The driving member 8 is an electric slider, or the two driving members 8 move back or toward each other with an electric lead screw as a power source, and have a waterproof function. The driving member 8 is used to drive the elastic telescopic rod 9 thereon to move along the sealing edge in the middle of the plastic bag. The electric rotating shaft on the elastic telescopic rod 9 is used to drive the L-shaped frame 10 to rotate, so that the L-shaped frame 10 squeezes the sealing edge in the middle of the plastic bag and flips it. When in use, the two L-shaped frames 10 cooperate with each other, one of the L-shaped frames 10 probes into between the outer side surface and the sealing edge of the plastic bag, and the other L-shaped frame 10 cooperates to fix the other side of the sealing edge of the plastic bag.

[0023] Further, if Figure 6 and Figure 7 As shown, the separation mechanism includes a rotating plate 11, which is rotatably connected to an adjacent L-shaped frame 10, a torsion spring 12 is fixedly connected between the rotating plate 11 and the L-shaped frame 10, the L-shaped frame 10 is rotatably connected to a limiting plate 13, a pull rope 14 is fixedly connected between the limiting plate 13 and the rotating plate 11, and the telescopic end of the elastic telescopic rod 9 is located on the rotation path of the limiting plate 13.

[0024] Further, if Figure 6 and Figure 7 As shown, the angle between the rotating plate 11 and a portion of the elastic telescopic rod 9 and the L-shaped frame 10 is equal to the maximum rotation angle thereof.

[0025] Further, if Figure 6 and Figure 7 As shown, an elastic plate 15 is fixedly connected between the rotating plate 11 and the adjacent L-shaped frame 10, and the elastic plate 15 is used to support the sealing edge of the plastic bag.

[0026] The above scheme provides a method for adjusting the supporting position of the sealed edge of the plastic bag during the process of turning over the sealed edge of the plastic bag; the position of the rear L-shaped frame 10 and the parts thereon is used as a reference, and the front end of the rotating plate 11 is initially in contact with the adjacent L-shaped frame 10, which is used to make the rotating plate 11 enter between the sealed edge in the middle of the plastic bag and the adjacent surface of the plastic bag. The rotating plate 11 is used to fix the edge of the sealed edge in the middle of the plastic bag, and the torsion spring 12 is always in a power storage state, which is used to ensure the stability of the initial position of the rotating plate 11 and the L-shaped frame 10. The limiting plate 13 drives the rotating plate 11 to rotate by pulling the pull rope 14, and the L-shaped frame 10 can be provided with A guide wheel is provided for guiding the pull rope 14, so that the front end of the rotating plate 11 is separated from the L-shaped frame 10 and gradually moves toward the edge of the sealed edge in the middle of the plastic bag. The relative rotation angle between the L-shaped frame 10 and the rotating plate 11 is used to make the rotating plate 11 parallel to the upper part of the L-shaped frame 10 after the L-shaped frame 10 stops rotating. The elastic plate 15 is located at the front side of the rotating plate 11 and the front side of the upper part of the adjacent L-shaped frame 10. The elastic plate 15 is used to support the sealed edge of the plastic bag, increase the contact surface between the device and the sealed edge of the plastic bag, and prevent the sealed edge of the plastic bag from rotating in the opposite direction and resetting after the rotating plate 11 is accidentally separated from the plastic bag.

[0027] Further, if Figure 4-Figure 6 As shown, it also includes a limiting component, which is arranged on the supporting shell 7. The limiting component is used to limit the height of the L-shaped frame 10. The limiting component includes limiting rods 16 whose number is the same as the number of elastic telescopic rods 9. The limiting rods 16 are fixed to the telescopic parts of adjacent elastic telescopic rods 9. The supporting shell 7 is fixed with two symmetrically distributed guide strips 17, and the guide strips 17 are used to limit the height of adjacent limiting rods 16.

[0028] The above scheme provides a way to increase the contact area with the sealing edge of the plastic bag; the guide strip 17 is V-shaped, and the opening of the guide strip 17 faces upward, and the limiting rod 16 contacts the lower edge of the guide strip 17. Taking the moving direction of the left-side driving member 8 as an example, during the movement of the driving member 8 to the left, the guide strip 17 limits the height of the telescopic end of the elastic telescopic rod 9 through the limiting rod 16, so that the telescopic end of the elastic telescopic rod 9 drives the L-shaped frame 10 to gradually move upward, so that the height of the L-shaped frame 10 changes with the lower side of the plastic bag, preventing the L-shaped frame 10 from separating from the sealing edge in the middle of the plastic bag. Initially, the elastic member in the elastic telescopic rod 9 is in a power storage state.

[0029] Working process: During the process of transporting food on the conveyor belt, when it is necessary to inspect the food packaging, the staff randomly selects the plastic bag packaging on the conveyor belt, and then injects water into the detection shell 2 to make the water level close to the lower side of the support plate 5. After the water injection is completed, the staff puts the sealed edge of the middle of the plastic bag to be tested downward and in a left-right direction on the upper side of the support plate 5, and then the staff starts the electric shaft on the telescopic end of the elastic telescopic rod 9. The following uses the example of the L-shaped frame 10 on one of the elastic telescopic rods 9 on the rear side probing into the middle of the plastic bag The sealed edge and the side of the plastic bag, the electric shaft on the telescopic end of the elastic telescopic rod 9 drives the L-shaped frame 10 to rotate counterclockwise ( Figure 1 In the figure, viewed from right to left), the L-shaped frame 10 drives the rotating plate 11 and the limiting plate 13 to rotate synchronously.

[0030] During the rotation of the L-shaped frame 10, when the L-shaped frame 10 penetrates between the sealed edge of the plastic bag and the adjacent surface of the plastic bag, the L-shaped frame 10 squeezes the adjacent position of the sealed edge of the plastic bag through the elastic plate 15 and the rotating plate 11, so that the sealed edge of the plastic bag is gradually turned over. In this process, when the limit plate 13 contacts the telescopic end of the elastic telescopic rod 9, the limit plate 13 stops rotating and pulls the rotating plate 11 through the pull rope 14, so that the rotating plate 11 rotates counterclockwise relative to the L-shaped frame 10 and stretches the elastic plate 15 ( Figure 1 , viewed from right to left), so that the flip angle of the sealed edge in the middle of the plastic bag gradually increases, until the rear side of the L-shaped frame 10 is in a vertical state, the electric shaft on the telescopic end of the elastic telescopic rod 9 stops driving the L-shaped frame 10 to rotate, the limit plate 13 and the L-shaped frame 10 stop rotating relative to each other, at this time the rotating plate 11 is in a horizontal state, the elastic plate 15 stops being stretched and fits with the adjacent surface of the sealed edge in the middle of the plastic bag.

[0031] After the L-shaped frame 10 stops rotating, the two driving members 8 drive the parts thereon to move in opposite directions, so that the elastic plates 15 on the two driving members 8 gradually flip the sealing edges of the plastic bag from the middle to the left and right sides. When the two driving members 8 move to the left and right edges of the supporting shell 7 respectively, the driving members 8 stop driving the parts thereon to move.

[0032] After the above-mentioned driving member 8 stops driving the elastic telescopic rod 9 to move, the electric rotating shaft on the fixed frame 1 is started, and the electric rotating shaft on the fixed frame 1 drives the sealing cover 4 to rotate through the rotating frame 3 until the axis of the sealing cover 4 coincides with the axis of the detection shell 2, the electric rotating shaft on the fixed frame 1 is closed, and the rotating frame 3 drives the sealing cover 4 to move downward through the telescopic end of the electric telescopic rod thereon. During the downward movement of the sealing cover 4, when the sealing cover 4 contacts the transmission rod 6, the sealing cover 4 drives the support plate 5 and the parts thereon to move downward by squeezing the transmission rod 6, and the support plate 5 moves and compresses the first spring 501 until the upper side of the sealing cover 4 contacts the detection shell 2, the electric telescopic rod on the rotating frame 3 stops driving the sealing cover 4 to move downward and completes the sealing detection shell 2, the support plate 5 stops moving downward and the plastic bag completely enters the water, and then the staff starts the vacuum pump to extract the gas from the detection shell 2, so that a pressure difference occurs inside and outside the plastic bag. At this time, the staff observes whether the plastic bag is leaking and the location of the leak, so as to facilitate the staff to adjust the production of the plastic bag.

[0033] After the inspection is completed, the driving member 8 drives the parts thereon to move in the opposite direction and reset, the electric rotating shaft on the elastic telescopic rod 9 drives the L-shaped frame 10 and the parts thereon to rotate in the opposite direction and reset and release the fixation of the sealing edge of the plastic bag, the electric telescopic rod on the rotating frame 3 drives the sealing cover 4 to reset, and the first spring 501 pushes the support plate 5 to move upward and reset, and then the staff takes out the plastic bags that have been inspected and inspects other plastic bags to be tested.

[0034] Further, if Figure 3 , Figure 8 and Fig. 9 As shown, it also includes symmetrically distributed adjustment components, which are all arranged on the support plate 5. The adjustment components are used to adjust the position of the plastic bag. The adjustment components include: a positioning frame 18, the positioning frame 18 is slidably connected to the support plate 5, the positioning frame 18 is fixedly connected to a positioning plate 19, the positioning plate 19 is slidably connected to the support plate 5, and the upper part of the transmission rod 6 is higher than the upper part of the positioning plate 19, the positioning plate 19 is used to adjust the position of the plastic bag, a second spring 20 is fixedly connected between the positioning frame 18 and the support plate 5, the detection shell 2 is fixedly connected to a vibration plate 21, and a plurality of protrusions are arranged on one side of the vibration plate 21 close to the adjacent positioning plate 19, and the protrusions on the vibration plate 21 are used to squeeze the positioning frame 18, and two symmetrically distributed fixing components are arranged on the support plate 5, and the fixing components are used to fix the adjacent sealing edges of the plastic bag.

[0035] Further, if Fig. 9 As shown, the height of the protrusion with the largest distance between the vibration plate 21 and the support plate 5 is greater than the heights of the other protrusions, so as to enable the positioning plate 19 to limit the position of the plastic bag.

[0036] Further, if Fig. 9As shown, the upper portion of the positioning plate 19 is arc-shaped, and the upper portion of the positioning plate 19 is deflected toward the center direction of the supporting plate 5 .

[0037] The above scheme provides a way to adjust the position of the plastic bag so that the position of the plastic bag is unified; the upper part of the positioning plate 19 is arc-shaped and gradually deflects toward the center of the support plate 5. The arc surface of the upper part of the positioning plate 19 is used to provide a downward thrust to the plastic bag to prevent the plastic bag from floating upward under the action of water buoyancy. The second spring 20 is used to push the positioning frame 18 to reset, and the vibration plate 21 drives the positioning frame 18 to move back and forth, so that the positioning plate 19 squeezes the side of the plastic bag, thereby adjusting the position of the plastic bag. The height of the lowermost protrusion on the vibration plate 21 is used to increase the positioning plate 19 to limit the position of the plastic bag. Initially, the distance between the two positioning plates 19 is greater than the width of the plastic bag, which is used to allow the two positioning plates 19 to separate from the plastic bag.

[0038] Workflow: In the process of placing the plastic bag, the staff puts the plastic bag between the two positioning plates 19. In the process of the sealing cover 4 pressing the transmission rod 6 downward, as the support plate 5 drives the parts on it to move downward, when the positioning frame 18 contacts the vibration plate 21 (taking the moving direction of the front positioning frame 18 and the parts on it as an example), the positioning frame 18 reciprocates back and forth under the action of the protrusion on the vibration plate 21 and the adjacent second spring 20, and the positioning frame 18 drives the positioning plate 19 to move synchronously, so that the positioning plate 19 intermittently squeezes the adjacent side of the plastic bag, thereby adjusting the position of the plastic bag so that the plastic bag is located in the middle of the support plate 5. As the support plate 5 continues to drive the parts on it to move downward, when the positioning frame 18 contacts the rear side of the lowest protrusion on the vibration plate 21, the positioning frame 18 moves downward along the rear side of the protrusion, so that the positioning plate 19 no longer moves forward and backward, and the positioning plate 19 squeezes the adjacent position of the plastic bag to complete the fixation, and then the staff starts the electric shaft on the elastic telescopic rod 9 to rotate the L-shaped frame 10 and repeat the above process to drive the sealing edge in the middle of the plastic bag to flip and detect.

[0039] Further, if Figure 2 , Figure 3 and Fig.10 As shown, it also includes a power component, which is arranged on the rotating frame 3 and is used to squeeze the plastic bag. The power component includes: an electric push rod 30, the electric push rod 30 is fixedly connected to the rotating frame 3, the telescopic end of the electric push rod 30 is slidably connected to the rotating frame 3, the telescopic end of the electric push rod 30 is fixedly connected to a connecting pipe 31, the connecting pipe 31 is externally connected to an air pump through the connecting pipe, the connecting pipe 31 is slidably connected to the sealing cover 4, the connecting pipe 31 is slidably connected and connected to a suction cup 32, and the suction cup 32 is used to fix the plastic bag.

[0040] Further, if Figure 2 , Figure 3 and Fig.10 As shown, a fourth spring 33 is fixedly connected between the connecting pipe 31 and the sealing cover 4 , and an extrusion frame 34 is fixedly connected to the connecting pipe 31 . The extrusion frame 34 evenly squeezes the plastic bag through the suction cup 32 .

[0041] The above scheme provides a method for increasing the exhaust speed by squeezing the plastic bag when there is a leak in the plastic bag; the air pump is used to extract the gas in the connecting pipe 31, so that negative pressure appears in the suction cup 32 to fix the plastic bag, and the suction cup 32 is made of rubber material to enable it to be deformed. The extrusion frame 34 is composed of a ring and four round rods. When the plastic bag discharges bubbles, but the bubble volume is small and difficult to observe, the round rods of the extrusion frame 34 squeeze the different positions of the suction cup 32, so that the suction cup 32 evenly squeezes the plastic bag, thereby accelerating the exhaust speed of the plastic bag and making its shape change evenly. In this embodiment, the initial position of the rotating frame 3 is as follows: Figure 1 shown.

[0042] Workflow: When it is necessary to take out the plastic bag from the conveyor belt, the staff starts the electric shaft on the fixed frame 1, so that the electric shaft drives the rotating frame 3 to rotate 90° counterclockwise ( Figure 1 , viewed from top to bottom), then the electric push rod 30 is started, the telescopic end of the electric push rod 30 drives the connecting pipe 31 to move downward, and the connecting pipe 31 drives the sealing cover 4 and the suction cup 32 to move downward, until the suction cup 32 contacts the plastic bag, the electric push rod 30 is closed, the suction cup 32 stops moving, and the staff starts the air pump, which extracts the gas in the connecting pipe 31 through the hose, so that negative pressure appears between the suction cup 32 and the upper side of the plastic bag, thereby adsorbing the plastic bag on the suction cup 32, and then the telescopic end of the electric push rod 30 is retracted and reset, and the electric shaft on the fixed frame 1 drives the rotating frame 3 to rotate in the opposite direction and reset. After the axis of the rotating frame 3 coincides with the axis of the sealing cover 4, the telescopic end of the electric push rod 30 drives the sealing cover 4 and the parts thereon to move downward again through the connecting pipe 31. When the sealing cover 4 contacts the transmission rod 6, the air pump is closed to restore the air pressure in the connecting pipe 31. The plastic bag loses its fixation and falls to the upper side of the support plate 5. Then the sealing cover 4 repeats the above process to squeeze the transmission rod 6 downward, so that the support plate 5 drives the parts thereon to move downward and fix the plastic. Until the upper side surface of the detection shell 2 contacts the sealing cover 4, the electric push rod 30 is closed, and then the above process is repeated to fix the sealing edge of the plastic bag.

[0043] In the above-mentioned process of testing plastic bags, when the plastic bag is damaged or leaking, the staff starts the electric push rod 30 again, and the telescopic end of the electric push rod 30 drives the connecting pipe 31 to move downward relative to the sealing cover 4 and compresses the fourth spring 33. The connecting pipe 31 drives the suction cup 32 and the extrusion frame 34 to move downward synchronously until the suction cup 32 contacts the plastic bag, and then the suction cup 32 stops moving. The extrusion frame 34 moves downward relative to the suction cup 32, so that the extrusion frame 34 squeezes the plastic bag through the suction cup 32, speeding up the exhaust speed of the plastic bag and making the deflation position of the plastic bag more obvious, thereby facilitating the staff to observe. After the inspection is completed, the telescopic end of the electric push rod 30 drives the parts on it to move upward and reset, and the staff takes out the tested plastic bag, and then repeats the above process for sampling and testing other plastic bags.

[0044] The above is only an example of the present invention and is not intended to limit the present invention. Any equivalent substitutions made within the principles of the present invention should be included in the protection scope of the present invention. The contents not elaborated in detail in the present invention belong to the existing technologies known to technicians in this professional field.

Claims

1. An air tightness detection device for packaging plastic bags, characterized in that: The invention comprises a fixed frame (1), the fixed frame (1) being provided with a detection shell (2), the detection shell (2) being connected to a vacuum pump via a hose, the fixed frame (1) being provided with an electric rotating shaft, the electric rotating shaft of the fixed frame (1) being provided with a rotating frame (3), the rotating frame (3) being provided with a sealing cover (4), the sealing cover (4) being used to seal the detection shell (2), a support plate (5) being slidably connected inside the detection shell (2), a first spring (501) being provided between the support plate (5) and the detection shell (2), and a transmission rod being fixedly connected to the upper side of the support plate (5) (6), the transmission rod (6) is located on the moving path of the sealing cover (4), the lower side of the support plate (5) is fixedly connected to a support shell (7), the support shell (7) is provided with symmetrically distributed driving members (8), the driving members (8) are fixedly connected to two symmetrically distributed elastic telescopic rods (9), the telescopic ends of the elastic telescopic rods (9) are provided with electric rotating shafts, the electric rotating shaft is fixedly connected to an L-shaped frame (10), the L-shaped frame (10) is used to flip the sealing edge in the middle of the plastic bag, and the L-shaped frame (10) is provided with a separation mechanism for driving the sealing edge in the middle of the plastic bag to rotate.

2. The air tightness detection device for packaging plastic bags according to claim 1, characterized in that: The separation mechanism comprises a rotating plate (11), the rotating plate (11) is rotatably connected to the adjacent L-shaped frame (10), a torsion spring (12) is fixedly connected between the rotating plate (11) and the L-shaped frame (10), the L-shaped frame (10) is rotatably connected to a limit plate (13), a pull rope (14) is fixedly connected between the limit plate (13) and the rotating plate (11), and the telescopic end of the elastic telescopic rod (9) is located on the rotation path of the limit plate (13).

3. The air tightness detection device for packaging plastic bags according to claim 2, characterized in that: The angle between the rotating plate (11) and a portion of the elastic telescopic rod (9) and the L-shaped frame (10) is equal to the maximum rotation angle thereof.

4. The air tightness detection device for packaging plastic bags according to claim 2, characterized in that: An elastic plate (15) is fixedly connected between the rotating plate (11) and the adjacent L-shaped frame (10), and the elastic plate (15) is used to support the sealing edge of the plastic bag.

5. The air tightness detection device for packaging plastic bags according to claim 4, characterized in that: The invention also comprises a limiting component, wherein the limiting component is arranged on the supporting shell (7), and is used to limit the height of the L-shaped frame (10). The limiting component comprises limiting rods (16) whose number is the same as the number of the elastic telescopic rods (9), and the limiting rods (16) are fixedly connected to the telescopic parts of the adjacent elastic telescopic rods (9). The supporting shell (7) is fixedly connected with two symmetrically distributed guide strips (17), and the guide strips (17) are used to limit the height of the adjacent limiting rods (16).

6. The air tightness detection device for packaging plastic bags according to claim 1, characterized in that: The invention also comprises symmetrically distributed adjustment components, which are all arranged on the support plate (5), and are used to adjust the position of the plastic bag. The adjustment components comprise: a positioning frame (18), which is slidably connected to the support plate (5), and the positioning frame (18) is fixedly connected to a positioning plate (19), which is slidably connected to the support plate (5), and the upper part of the transmission rod (6) is higher than the upper part of the positioning plate (19), and the positioning plate (19) is used to adjust the position of the plastic bag. A second spring (20) is fixedly connected between the positioning frame (18) and the support plate (5), and the detection shell (2) is fixedly connected to a vibration plate (21), and a plurality of protrusions are arranged on a side of the vibration plate (21) adjacent to the positioning plate (19), and the protrusions on the vibration plate (21) are used to press the positioning frame (18). Two symmetrically distributed fixing components are arranged on the support plate (5), and the fixing components are used to fix the adjacent sealing edges of the plastic bag.

7. The air tightness detection device for packaging plastic bags according to claim 6, characterized in that: The height of the protrusion with the largest distance between the vibration plate (21) and the support plate (5) is greater than the heights of the other protrusions, and is used to enable the positioning plate (19) to limit the position of the plastic bag.

8. The air tightness detection device for packaging plastic bags according to claim 6, characterized in that: The upper portion of the positioning plate (19) is arc-shaped, and the upper portion of the positioning plate (19) is deflected towards the center direction of the support plate (5).

9. The air tightness detection device for packaging plastic bags according to claim 1, characterized in that: The invention also comprises a power assembly, the power assembly being arranged on the rotating frame (3), the power assembly being used for squeezing the plastic bag, the power assembly comprising: an electric push rod (30), the electric push rod (30) being fixedly connected to the rotating frame (3), the telescopic end of the electric push rod (30) being slidably connected to the rotating frame (3), the telescopic end of the electric push rod (30) being fixedly connected to a connecting pipe (31), the connecting pipe (31) being externally connected to an air pump through the connecting pipe, the connecting pipe (31) being slidably connected to the sealing cover (4), the connecting pipe (31) being slidably connected to and connected to a suction cup (32), the suction cup (32) being used for fixing the plastic bag.

10. The air tightness detection device for packaging plastic bags according to claim 9, characterized in that: A fourth spring (33) is fixedly connected between the connecting tube (31) and the sealing cover (4), and an extrusion frame (34) is fixedly connected to the connecting tube (31). The extrusion frame (34) evenly squeezes the plastic bag through the suction cup (32).

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