Adjustable convenient gas collection cover

Abstract

The utility model discloses an adjustable convenient gas collection cover relates to environmental protection experimental instrument field, and the outer surface of the support frame structure that is composed of main body telescopic frame and rubber air cushion ring is covered connected to the plastic film component, forms the gas collection space of bottom opening, and the position of plastic film component is close to rubber air cushion ring and is provided with two gas inlets. The utility model discloses adjustable support structure is built to the main body telescopic frame and rubber air cushion ring of detachable joint, and the plastic film component that cooperates and is covered in the outer surface of frame forms the gas collection space of bottom opening, and simultaneously integrated gas inlet realizes air pressure balance, to solve the core defect of traditional device volume unadjustable, transportation is heavy and poor resistance to damage.

Description

Technical Field

[0001] This utility model relates to the field of environmental protection experimental instruments, and in particular to an adjustable and convenient gas collection hood. Background Technology

[0002] In the field of environmental monitoring and gas sampling, fixed-volume gas collection devices are widely used in in-situ monitoring scenarios for air pollutants and greenhouse gases. These devices typically use rigid enclosures made of acrylic or glass to capture target gases within a sealed space and then use analytical instruments to achieve quantitative detection, providing fundamental technical support for environmental research.

[0003] However, existing gas collection devices have three significant drawbacks: First, the volume of traditional enclosures is fixed and cannot be flexibly adjusted according to actual sampling needs. Customized equipment is required for measurement areas of different volumes, resulting in high experimental costs and low resource utilization. Second, solid materials such as acrylic / glass have high density and bulky structures, occupying a lot of space during field transportation and storage. Especially for large-volume collection enclosures, relocation difficulties greatly limit their site adaptability. Third, rigid materials have poor impact resistance and are prone to breakage due to bumps or pressure in complex field environments. This not only damages the equipment and interrupts the monitoring process but may also lead to the leakage of harmful gases due to sudden damage, posing a safety hazard.

[0004] Therefore, how to develop an adjustable and convenient gas collection hood, which uses a detachable snap-fit ​​main telescopic frame and rubber gaskets to construct an adjustable support structure, and uses a plastic film component covering the outer surface of the frame to form a gas collection space with an opening at the bottom, while integrating an air inlet to achieve air pressure balance, in order to solve the core defects of traditional devices such as non-adjustable volume, heavy transportation and poor damage resistance, has become a technical problem that urgently needs to be solved by people in this field. Utility Model Content

[0005] The purpose of this invention is to provide an adjustable and convenient gas collection hood. It uses a detachable and snap-fit ​​telescopic frame and a rubber gasket to construct an adjustable support structure. A plastic film assembly covering the outer surface of the frame forms a gas collection space with an opening at the bottom. At the same time, an integrated air inlet is used to achieve air pressure balance, thereby solving the core defects of traditional devices such as non-adjustable volume, heavy transportation, and poor damage resistance.

[0006] To solve the above-mentioned technical problems, the present invention adopts the following technical solution:

[0007] This utility model discloses an adjustable and convenient gas collection hood, comprising a main telescopic frame, a plastic film assembly, and a rubber gasket. The main telescopic frame is detachably snapped onto the top of the rubber gasket, together forming an adjustable support frame structure. The plastic film assembly covers and connects to the outer surface of the support frame structure composed of the main telescopic frame and the rubber gasket, forming a gas collection space with an open bottom. The plastic film assembly is provided with two gas inlets near the rubber gasket.

[0008] Preferably, the main telescopic frame includes a telescopic ring, a lifting ring, a connecting rod, a telescopic rod assembly, and a first C-shaped retaining ring. The lifting ring is coaxially arranged with the telescopic ring. One end of the connecting rod is hinged to the outer ring wall of the lifting ring via a first rotating shaft, and the other end of the connecting rod is hinged to the inner ring wall of the telescopic ring via a second rotating shaft. The telescopic end of the telescopic rod assembly is hinged to the outer ring wall of the telescopic ring via the second rotating shaft, and the fixed end of the telescopic rod assembly is engaged with the rubber gasket via the first C-shaped retaining ring. The number of connecting rods and telescopic rod assemblies is equal, and each is set to at least three.

[0009] Preferably, the telescopic rod assembly includes an outer tube and at least two coaxially sleeved telescopic tube segments. The telescopic tube segments are slidably fitted together to achieve telescopic movement. The telescopic end of the telescopic rod assembly is the free end of the innermost telescopic tube segment, and the fixed end of the telescopic rod assembly is the base end of the outermost telescopic tube segment. The first C-shaped retaining ring is fixedly connected to the base end of the outermost telescopic tube segment.

[0010] Preferably, the rubber air cushion ring includes multiple metal support rings and multiple rubber ring sections, the rubber ring sections and the metal support rings are alternately arranged, and two adjacent rubber ring sections are connected by a metal support ring to form a ring structure. Each rubber ring section is independently sealed and has an independent inflation hole.

[0011] Preferably, each of the metal support rings has a buckle on its outer peripheral side, and adjacent metal support rings are detachably and fixedly connected together by the buckle.

[0012] Preferably, the plastic film assembly further includes a plastic film body and movable rods. The plastic film body is sleeved and connected to the outer surface of the support frame structure. At least two movable rods are tightly attached to the outer surface of the plastic film body. The top of each movable rod is provided with a U-shaped hook, which engages with the telescopic ring and clamps and fixes the plastic film body to the telescopic ring. The bottom of each movable rod is fixedly connected with a second C-shaped retaining ring for engaging with the rubber air cushion. The bottom opening edge of the plastic film body is fitted to the outer surface of the rubber air cushion and is pressed and fixed by the second C-shaped retaining ring.

[0013] Preferably, the plastic film body includes a circular top and a rectangular side, the two sides of the rectangular side are connected end to end and integrally formed with the circular top to form a gas collection space with a bottom opening, and the gas inlet is opened on the bottom side of the rectangular side.

[0014] The outer surface of the circular top is provided with multiple first suction cup buckles along its radial direction for adsorbing and fixing the excess part of the top of the plastic film body; multiple second suction cup buckles are provided on both sides of the moving rod for adsorbing and fixing the excess part of the side of the plastic film body.

[0015] Compared with the prior art, the beneficial technical effects of this utility model are as follows:

[0016] 1) This invention achieves flexible adjustment of the volume of the cover space by adjusting the diameter and height of the main telescopic frame, increasing or decreasing the number of effective working rings of the rubber air cushion, and adjusting the coverage area of ​​the plastic film component. This design enables a single device to meet the needs of various experimental spaces of different sizes, effectively solving the problem that traditional solutions require custom-made collection covers for specific sizes. This not only significantly improves the convenience of experimental preparation, but also avoids the additional material and processing costs caused by repeated customization, thereby significantly reducing the overall investment in the experiment.

[0017] 2) This invention abandons the traditional rigid integrated structure and adopts a telescopic and foldable aluminum alloy main frame, a modular rubber air cushion that can be folded and stored in sections, and a detachable flexible plastic film component. This highly modular and foldable design allows the entire device to be easily disassembled, folded and compactly stored when not in use, which greatly reduces the volume and space occupied during transportation and storage, effectively solves the core problem of the difficulty in transporting large gas collection hoods, and significantly improves the preparation efficiency and operational portability of field gas measurement work.

[0018] 3) The main frame of this invention, made of 6061 aluminum alloy, combines lightweight and high hardness, ensuring support strength and stability under repeated expansion and contraction. The flexible LLDPE plastic film replaces the brittle acrylic material, possessing excellent tear resistance and low-temperature flexibility, and can elastically deform to absorb impact under pressure. The neoprene rubber air cushion joint has excellent oil resistance, ozone resistance, UV aging resistance, and wear resistance. This combination of aluminum alloy frame and flexible film, along with the application of weather-resistant rubber, significantly improves the overall ability of the device to resist transportation bumps and physical damage during use, reduces the risk of damage caused by accidental collisions or environmental factors in complex outdoor environments, and extends its service life. Attached Figure Description

[0019] The present invention will be further described below with reference to the accompanying drawings.

[0020] Figure 1 This is a schematic diagram of the overall structure of an adjustable and convenient gas collection hood according to the present invention;

[0021] Figure 2 This is a schematic diagram of the main telescopic frame of this utility model;

[0022] Figure 3 This is a schematic diagram of the connection structure between the plastic film assembly and the rubber gasket of this utility model;

[0023] Figure 4 This is a schematic diagram of the structure of the movable rod of this utility model;

[0024] Figure 5 This is a schematic diagram of the structure of the rubber air cushion of this utility model;

[0025] Figure 6 This is a partial structural schematic diagram of the rubber air cushion of this utility model;

[0026] Figure 7 This is a schematic diagram of the unfolded structure of the plastic film body of this utility model.

[0027] Explanation of reference numerals in the attached drawings: 1. Main telescopic frame; 11. Telescopic ring; 12. Lifting ring; 13. Connecting rod; 14. Telescopic rod assembly; 141. Outer tube; 142. Telescopic tube section; 15. First C-shaped retaining ring; 16. First rotating shaft; 17. Second rotating shaft; 2. Plastic film assembly; 21. Air inlet; 22. Plastic film body; 23. Moving rod; 24. U-shaped hook; 25. Second C-shaped retaining ring; 3. Rubber air cushion; 31. Metal support ring; 32. Rubber ring joint; 33. Inflation hole; 34. Ring buckle. Detailed Implementation

[0028] To make the technical problem to be solved, the technical solution, and the beneficial effects of this utility model clearer, the present utility model will be further described in detail below with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are only used to explain this utility model and are not intended to limit this utility model.

[0029] like Figure 1-7 As shown, an adjustable and convenient gas collection hood includes a main telescopic frame 1, a plastic film assembly 2, and a rubber air cushion 3. The main telescopic frame 1 is detachably snapped onto the top of the rubber air cushion 3, together forming an adjustable support frame structure. The plastic film assembly 2 covers and is connected to the outer surface of the support frame structure composed of the main telescopic frame 1 and the rubber air cushion 3, forming a gas collection space with an open bottom. The plastic film assembly 2 is provided with two air inlets 21 near the rubber air cushion 3.

[0030] Specifically, the main telescopic frame 1 includes a telescopic ring 11, a lifting ring 12, a connecting rod 13, a telescopic rod assembly 14, and a first C-shaped retaining ring 15. The lifting ring 12 is coaxially arranged with the telescopic ring 11. One end of the connecting rod 13 is hinged to the outer ring wall of the lifting ring 12 through a first rotating shaft 16, and the other end of the connecting rod 13 is hinged to the inner ring wall of the telescopic ring 11 through a second rotating shaft 17. The telescopic end of the telescopic rod assembly 14 is hinged to the outer ring wall of the telescopic ring 11 through the second rotating shaft 17, and the fixed end of the telescopic rod assembly 14 is snapped into the rubber air cushion 3 through the first C-shaped retaining ring 15. The number of connecting rods 13 and telescopic rod assemblies 14 is equal, and each is set to at least three.

[0031] Specifically, the telescopic rod assembly 14 includes an outer tube 141 and at least two coaxially sleeved telescopic tube segments 142. The telescopic tube segments 142 are connected by sliding fit to achieve telescopic movement. The telescopic end of the telescopic rod assembly 14 is the free end of the innermost telescopic tube segment 142, and the fixed end of the telescopic rod assembly 14 is the base end of the outermost telescopic tube segment 142. The first C-shaped retaining ring 15 is fixedly connected to the base end of the outermost telescopic tube segment 142.

[0032] Specifically, the main telescopic frame 1 is used to support the entire plastic film body 22. By adjusting the size of the main telescopic frame 1, the volume of the sealed space formed by the plastic film body 22 can be changed. This adjustable feature allows the gas collection hood to adapt to the space size requirements of different experiments.

[0033] This design effectively solves the problem of special experiments requiring custom-made gas collection hoods of specific sizes. A single device can meet various spatial size requirements, which not only significantly improves the convenience of experiments but also avoids the additional material and processing costs incurred by customizing for a single size, thereby significantly reducing the overall cost of experiments.

[0034] Specifically, the telescopic ring 11 adopts a clamp-type telescopic ring structure. The ring body is designed to be radially telescopic, and a manually operated locking mechanism is provided on one side. By turning the locking mechanism, the diameter of the telescopic ring 11 can be easily adjusted and firmly locked in the required size position, thereby realizing continuous adjustment and reliable fixation of the ring body size.

[0035] Specifically, when the telescopic ring 11 is at its maximum diameter, the three connecting rods 13 are evenly distributed at 120-degree intervals around the telescopic ring 11.

[0036] Specifically, the main telescopic frame 1 is made of 6061 aluminum alloy, which has the characteristics of being lightweight (low density) and high hardness. While ensuring the structural support strength, it significantly reduces the overall weight of the frame, perfectly meeting the dual requirements of telescopic frames for lightweighting and structural strength, and ensuring structural stability and long service life during repeated telescopic adjustments.

[0037] Specifically, the rubber air cushion 3 includes multiple metal support rings 31 and multiple rubber ring sections 32. The rubber ring sections 32 and the metal support rings 31 are alternately arranged. Two adjacent rubber ring sections 32 are connected by a metal support ring 31 to form a ring structure. Each rubber ring section 32 is independently sealed and has an independent inflation hole 33.

[0038] Specifically, each of the metal support rings 31 has a buckle 34 on its outer peripheral side, and adjacent metal support rings 31 are detachably and fixedly connected together by the buckle 34.

[0039] Specifically, the rubber ring 32 is made of neoprene. This material has excellent oil resistance, ozone resistance, UV aging resistance, and strong wear resistance, significantly improving the service life of the ring in complex environments and making it suitable for field gas collection scenarios.

[0040] Specifically, the rubber air cushion 3 itself is a complete ring structure of a preset length, and its circumference and diameter can be adjusted through the following operations:

[0041] First, determine the number of rubber rings 32 that need to be retained in an effective working state based on the required bottom dimensions of the cover;

[0042] Then, using the ring buckle 34 set on the outer periphery of the metal support ring 31, the redundant rubber ring section 32 that does not need to participate in the effective sealing and its corresponding metal support ring 31 are folded and fixed together, so that they are removed from the effective working area. At this time, the remaining ring section that is not folded and fixed naturally maintains its original ring connection state, forming an effective closed-loop structure with reduced size.

[0043] Finally, all rubber rings 32 in the effective closed loop are individually inflated to expand them and achieve a bottom seal;

[0044] By increasing or decreasing the number of rubber ring sections 32 that remain in the effective working state, the effective diameter of the rubber gasket 3 can be adjusted in a stepwise manner, thereby ensuring that the gas collection hood can accurately adapt to measurement areas of different sizes.

[0045] Specifically, the plastic film assembly 2 further includes a plastic film body 22 and a moving rod 23. The plastic film body 22 is sleeved and connected to the outer surface of the support frame structure. At least two moving rods 23 are tightly attached to the outer surface of the plastic film body 22. The top of the moving rod 23 is provided with a U-shaped hook 24, which is engaged with the telescopic ring 11 and clamps and fixes the plastic film body 22 to the telescopic ring 11. The bottom of the moving rod 23 is fixedly connected with a second C-shaped retaining ring 25 for engaging with the rubber air cushion 3. The bottom opening edge of the plastic film body 22 is attached to the outer surface of the rubber air cushion 3 and is pressed and fixed by the second C-shaped retaining ring 25.

[0046] Specifically, the plastic film body 22 includes a circular top and a rectangular side. The two sides of the rectangular side are connected end to end and are integrally formed with the circular top to form a gas collection space with a bottom opening. The gas inlet 21 is opened on the bottom side of the rectangular side.

[0047] The outer surface of the circular top is provided with a plurality of first suction cup buckles along its radial direction for adsorbing and fixing the excess part of the top of the plastic film body 22; the two sides of the moving rod 23 are provided with a plurality of second suction cup buckles for adsorbing and fixing the excess part of the side of the plastic film body 22.

[0048] Specifically, the plastic film body 22 serves to enclose the gas to be measured within a fixed space formed by the main telescopic frame 1 and the rubber gasket 3. Two air inlets 21 are provided on its side, one as an inlet and the other as an outlet. During measurement, gas can simultaneously flow in through the inlet and out through the outlet to maintain the pressure balance inside the collection hood and ensure the accuracy of the gas measurement.

[0049] Specifically, the plastic film body 22 is made of linear low-density polyethylene (LLDPE) material, which has the following characteristics: light transmittance of 85% to 90% (low haze), strong tear resistance (its puncture toughness is 3 times that of low-density polyethylene), and excellent low-temperature flexibility (it can remain non-brittle at -60℃).

[0050] Specifically, the movable rod 23 is used to control and fix the position of the plastic film body 22. By adjusting the snapping position of the second C-shaped retaining ring 25 on the rubber gasket 3, the position of the movable rod 23 can be changed, thereby changing the folding area of ​​the plastic film body 22, and ultimately achieving the purpose of adjusting the effective gas collection volume formed by the plastic film body 22.

[0051] Specifically, in terms of material selection, this invention abandons the design of solid acrylic rigid plates commonly used in traditional gas collection hoods. The main body (i.e., the plastic film body 22) uses flexible plastic film instead of acrylic material, which makes the weight of the entire gas collection hood significantly reduced, especially when testing gas in a large volume space, and the structure more compact, thereby greatly improving the portability and ease of operation of the device.

[0052] Specifically, in terms of structural design, this invention abandons the rigid, integrated structure of traditional gas collection hoods. Instead, it adopts a retractable and foldable main telescopic frame 1 and segmented, adjustable rubber gaskets 3, along with a detachable connection method. This allows the entire device to be designed as a highly foldable or retractable modular component. This innovative design enables the main parts of the device to be easily disassembled, folded, and compactly stored before or during field sampling and transportation. This greatly reduces the volume and space occupied by the transport equipment, effectively solves the core problem of the difficulty in transporting large-volume gas collection hoods, and significantly improves the preparation efficiency and operational convenience of field gas measurement work.

[0053] Specifically, the material combination of this invention (aluminum alloy main telescopic frame 1 and flexible plastic film body 22) has significant advantages in resistance to physical damage compared to traditional solid acrylic covers. Traditional acrylic materials are brittle and easily break or crack when subjected to pressure or impact during transportation or use. In contrast, the aluminum alloy frame of this invention has high hardness and good toughness, and is not easily permanently deformed by impacts; simultaneously, the flexible plastic film can undergo elastic deformation under pressure, absorbing impact energy and is not easily broken. This combination of alloy frame and flexible film effectively improves the overall impact resistance of the device and reduces the risk of damage caused by accidental collisions in complex outdoor environments.

[0054] The usage process of this utility model is as follows:

[0055] First, the device is assembled and initially adjusted. According to the measurement space size requirements, the number of rubber rings 32 in the effective working state is increased or decreased to adjust the diameter of the rubber air cushion 3. The excess rubber rings 32 and the corresponding metal support rings 31 are folded and fixed by the ring buckle 34 so that the remaining rings form a closed loop. Then, all the rubber rings 32 in the effective closed loop are independently inflated through the inflation hole 33.

[0056] Next, the locking mechanism of the telescopic ring 11 is turned to adjust its diameter to the target size, and the telescopic tube section 142 is pulled to adjust the support height. Then, the U-shaped hook 24 of the plastic film assembly 2 is engaged on the telescopic ring 11, and the second C-shaped ring 25 at the bottom of the moving rod 23 is engaged on the rubber air cushion 3 to complete the assembly of the cover.

[0057] Then, gas collection and analysis are performed. The hood is placed on the surface of the area to be tested, and the external gas pipeline is connected to the two air inlets 21 on the side of the plastic film body 22. The air inlet and outlet are set to form a gas circulation path. During the measurement process, the gas continuously flows in from the air inlet and is discharged from the air outlet, dynamically maintaining the air pressure balance inside the hood and ensuring the accuracy of the test data.

[0058] Finally, after the experiment, the gas inside the rubber ring 32 is released; the connection of the first C-shaped retaining ring 15, the second C-shaped retaining ring 25 and the U-shaped hook 24 is released; the telescopic tube section 142 of the main telescopic frame 1 is retracted and reset, and the connecting rod 13 is folded and closed; the ring buckle 34 that fixes the redundant ring in the rubber air cushion 3 is unfolded to restore the complete ring; after disassembling each module, they are stacked compactly to reduce the transportation volume and facilitate repeated use in the field.

[0059] It should be noted that, in this document, relational terms such as "first" and "second" are used only to distinguish one entity or operation from another, and do not necessarily require or imply any such actual relationship or order between these entities or operations. Furthermore, the terms "comprising," "including," or any other variations thereof are intended to cover non-exclusive inclusion, such that a process, method, article, or apparatus that comprises a list of elements includes not only those elements but also other elements not expressly listed, or elements inherent to such process, method, article, or apparatus.

[0060] The embodiments described above are merely preferred embodiments of the present utility model and are not intended to limit the scope of the present utility model. Various modifications and improvements made to the technical solutions of the present utility model by those skilled in the art without departing from the spirit of the present utility model should fall within the protection scope defined by the claims of the present utility model.

Claims

1. An adjustable and convenient gas collection hood, characterized in that: The device includes a main telescopic frame (1), a plastic film assembly (2), and a rubber air cushion (3). The main telescopic frame (1) is detachably snapped onto the top of the rubber air cushion (3) to form an adjustable support frame structure. The plastic film assembly (2) covers and connects to the outer surface of the support frame structure composed of the main telescopic frame (1) and the rubber air cushion (3) to form a gas collection space with an open bottom. The plastic film assembly (2) has two air inlets (21) near the rubber air cushion (3).

2. The adjustable and convenient gas collection hood according to claim 1, characterized in that: The main telescopic frame (1) includes a telescopic ring (11), a lifting ring (12), a connecting rod (13), a telescopic rod assembly (14), and a first C-shaped retaining ring (15). The lifting ring (12) is coaxially arranged with the telescopic ring (11). One end of the connecting rod (13) is hinged to the outer ring wall of the lifting ring (12) through a first rotating shaft (16). The other end of the connecting rod (13) is hinged to the inner ring wall of the telescopic ring (11) through a second rotating shaft (17). The telescopic end of the telescopic rod assembly (14) is hinged to the outer ring wall of the telescopic ring (11) through the second rotating shaft (17). The fixed end of the telescopic rod assembly (14) is snapped to the rubber gasket (3) through the first C-shaped retaining ring (15). The number of the connecting rod (13) and the telescopic rod assembly (14) is equal, and each is set to at least three.

3. The adjustable and convenient gas collection hood according to claim 2, characterized in that: The telescopic rod assembly (14) includes an outer tube (141) and at least two coaxially sleeved telescopic tube segments (142). The telescopic tube segments (142) are connected by sliding fit to achieve telescopic movement. The telescopic end of the telescopic rod assembly (14) is the free end of the innermost telescopic tube segment (142), and the fixed end of the telescopic rod assembly (14) is the base end of the outermost telescopic tube segment (142). The first C-shaped retaining ring (15) is fixedly connected to the base end of the outermost telescopic tube segment (142).

4. The adjustable and convenient gas collection hood according to claim 3, characterized in that: The rubber air cushion (3) includes multiple metal support rings (31) and multiple rubber ring sections (32). The rubber ring sections (32) and the metal support rings (31) are alternately spaced. Two adjacent rubber ring sections (32) are connected by a metal support ring (31) to form a ring structure. Each rubber ring section (32) is independently sealed and has an independent air hole (33).

5. An adjustable and convenient gas collection hood according to claim 4, characterized in that: Each of the metal support rings (31) has a buckle (34) on its outer peripheral side, and adjacent metal support rings (31) are detachably and fixedly connected together by the buckle (34).

6. An adjustable and convenient gas collection hood according to claim 4, characterized in that: The plastic film assembly (2) further includes a plastic film body (22) and a moving rod (23). The plastic film body (22) is sleeved and connected to the outer surface of the support frame structure. At least two moving rods (23) are tightly attached to the outer surface of the plastic film body (22). The top of the moving rod (23) is provided with a U-shaped hook (24), which is engaged with the telescopic ring (11) and clamps and fixes the plastic film body (22) to the telescopic ring (11). The bottom of the moving rod (23) is fixedly connected with a second C-shaped retaining ring (25) for engaging with the rubber air cushion (3). The bottom opening edge of the plastic film body (22) is attached to the outer surface of the rubber air cushion (3) and is pressed and fixed by the second C-shaped retaining ring (25).

7. An adjustable and convenient gas collection hood according to claim 6, characterized in that: The plastic film body (22) includes a circular top and a rectangular side. The two sides of the rectangular side are connected end to end and integrally formed with the circular top to form a gas collection space with a bottom opening. The gas inlet (21) is opened on the bottom side of the rectangular side. The outer surface of the circular top is provided with a plurality of first suction cup buckles along its radial direction for adsorbing and fixing the excess part of the top of the plastic film body (22); the two sides of the moving rod (23) are provided with a plurality of second suction cup buckles for adsorbing and fixing the excess part of the side of the plastic film body (22).

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