Inflatable Tent Air Column Connection Structure and Manufacturing Method thereof and Mold thereof

Description

CROSS REFERENCE TO RELATED APPLICATIONS

The present application claims the benefit of Chinese Patent Application Nos. 2025100407016 filed on Jan. 10, 2025, 2024115695007 filed on Nov. 5, 2024 and 2025115147045 filed on Oct. 22, 2025. All the above are hereby incorporated by reference in their entirety.

TECHNICAL FIELD

The invention relates to an inflatable tent air column connection structure and manufacturing method thereof and mold thereof, and belongs to the technical field of air column production of the inflatable tent.

BACKGROUND ART

An inflatable tent generally has an inflatable tent frame formed by connecting multiple air columns, as shown in FIG. 1, so that inflatable tents are promoted for outdoor use due to their convenience in both storage and use. However, due to the structural features of the inflatable tent, a frame of an inflatable tent features multiple bent connections of air columns, such as a connection of two air columns, as shown in two adjacent air column structures (two-way connection structure 100) in FIG. 1. There are three-way connections of three air columns, or multiple-way connections of four or more air columns, as shown in a four-way air column structure 200 in FIG. 1. Most of the existing air column connection processes are performed by manual operation, this requires workers to manually align the edges of the air column cut pieces for welding sealing. Therefore, it is easy to occur that the air column connection is not in place or is not firm due to the poor control of the precision of material alignment during welding, leading to air leakage of the air columns and failing to ensure the quality of the welding and sealing of the air columns connection. In addition, in the manufacturing process of traditional technology, due to the uneven tension distribution of materials or the limitation of splicing process, the finished products often have structural distortion, deformation and other problems, affecting the aesthetic, durability and safety performance of the product.

Therefore, it is necessary to further improve and perfect the prior art to overcome these disadvantages, and the invention has been made based on this situation.

SUMMARY OF THE INVENTION

An object of the invention is to overcome the disadvantages of the prior art and provide an inflatable tent air column connection structure, which has good connection strength and good air tightness.

Another object of the invention is to provide a manufacturing method for the above-described connection structure of air columns for the inflatable tent.

The third object of the invention is to provide a mold for producing a V-shaped airtight sheet in the above-described connection structure.

The invention is achieved by the following technical solution.

An inflatable tent air column connection structure, comprising at least two pipe bodies in communication with each other, wherein a connection area of adjacent pipe bodies is provided with a first welding area for sealing and connecting the both; and the first welding area is provided with an airtight sheet covering the connection area of adjacent pipe bodies. It is preferred that the airtight sheet covers the entire welding area.

Preferably, the connection area of adjacent pipe bodies is provided with a reinforcing sheet covering the connection area; and the reinforcing sheet is attached to the other side of the airtight sheet or the other side of sheets of the pipe bodies.

The airtight sheet is made of flexible material, preferably one of the following: a PVC airtight sheet, a TPU airtight sheet, a mesh-reinforced airtight sheet and an EVA airtight sheet.

The airtight sheet is configured to be a sheet-like form matching the first welding area, or be an integrally formed V-shaped sheet. Both sides of the V-shaped sheet are respectively connected to the first welding area of the adjacent pipe body in an air-tight manner.

When there are multiple interconnected pipe bodies, inner and outer sides of convergence centers of the first welding areas are respectively provided with a central airtight patch and/or a central reinforcing patch covering the convergence center. The size of the central airtight patch is larger than the size of the central reinforcing patch.

A top center and a bottom center of each convergence center of the multiple first welding areas are both provided with a central hole, and an inner side and an outer side of a periphery of the central hole are respectively welded with the central airtight patch and the center reinforcing sheet.

The reinforcing sheet and the central reinforcing patch are both mesh-reinforced airtight reinforcing sheets.

A sealing liner can be provided between adjacent pipe bodies; the sealing liner includes sealing pipes with the same number and in communication with the pipe bodies; and edges of the sealing pipes are welded to inner walls of the corresponding pipe bodies.

The pipe body includes a pipe body sheet and is rolled from the pipe body sheet; and two long side edges of the pipe body sheet are respectively provided with a second welding area for sealing and connecting the both.

When another end of the pipe body is free and not connected to other pipe body, the free end of the pipe body is provided with an end sealing structure. The end sealing structure includes an outer flange provided at the free end of the pipe body; a sealing sheet and a bottom-closing sheet are successively provided below the outer flange; and the outer flange, a periphery of the sealing sheet and a periphery of the bottom-closing sheet are welded together to form a fourth welding area.

A manufacturing method for the above-mentioned inflatable tent air column connection structure, the method comprising:

• • S1, cutting and forming pipe body sheets;
  • S2, covering the welding area of each pipe body sheet with an airtight sheet;
  • S3, aligning and overlaying two pipe body sheets covered with the airtight sheets, while maintaining separation between the airtight sheets, and then welding the two pipe body sheets so that the airtight sheets hermatically cover the connection area of adjacent air columns.

A preferred one of the step S2 of the invention, welding an airtight sheet at a welding area on one side of each pipe body sheet, the airtight sheet extending outside of the pipe body sheet. Another preferred one of step S2 of the invention, the airtight sheet provided between the adjacent pipe body sheets is V-shaped; a connecting edge of the V-shaped airtight sheet is on the same side as a connecting end of the adjacent pipe body sheets; and both sides of the V-shaped airtight sheet respectively cover the welding areas of the corresponding pipe body sheets. When the both sides of the V-shaped airtight sheet are adjacent to each other, the welding is performed by separating the both sides of the V-shaped airtight sheet with a separation plate in the step S3.

The manufacturing method of the invention, further comprising:

• • S4, providing a reinforcing sheet covering the connecting end of the adjacent pipe body sheets on the airtight sheet, or providing a reinforcing sheet covering the connection area of the adjacent pipe body sheets on the other sides of the pipe body sheets; and
  • S5, welding both axial sides of each pipe body sheet for forming.

When there are a plurality of pipe bodies, after the step S4 is completed, arranging a central airtight patch and/or a central reinforcing patch at a convergence center of each pair of pipe conncetion connection area. Finally, forming each pipe body sheet into a pipe body.

A mold for the production of the above inflatable tent air column connection structure, the mold is used for producing the V-shaped airtight sheet, comprising a lower mold and an upper mold which is configured to ascend and descend, the lower mold is provided with a cambered surface having a shape consistent with a connecting end of the pipe body sheet; both sides of the cambered surface are respectively provided with an angled mold surface matching the connecting end shape of the pipe body sheet; the cambered surface and the angled mold surfaces correspond to a bottom groove and both sides of the V-shaped airtight sheet; the upper mold includes a positioning mold abutting against the cambered surface of the lower mold; two sides of the positioning mold are respectively provided with an upper side mold configured to ascend and descend elastically; and mold surfaces of the two upper side molds face each other, and can respectively match and close with the angled mold surfaces of the lower mold.

The positioning mold is provided with an upper mold base configured to ascend and descend elastically, and both of the upper side molds are connected to the upper mold base.

Compared to the prior art, the invention has the following advantages.

The welding area of the connection structure of the invention is provided with an airtight sheet to cover the connection area of adjacent pipe bodies in an airtight manner, which effectively improves the thickness and air-tightness of the welding area of the connection structure of the air column. The reinforcing sheet further improves the tensile resistance and prevents the air column from leaking due to tearing. In addition, a sealing structure for the free end of the pipe body, enabling adaption to different application scenarios and strength requirements, improving the compressive resistance and durability of the bottom of the supporting air column, effectively solving the problems of structural deformation or tearing caused by air pressure fluctuations, thereby providing a more reliable assurance for the use of the inflatable tent. The welding of whole ensures bonding and excellent sealing performance. The manufacturing method of the invention is simple, improves the production efficiency, reduces the production cost, improves the quality of the product, ensures that the airtight sheet is not damaged during the welding process, and ensures the air-tightness between the airtight sheet itself and the sheet of pipe body. Meanwhile, the method of the invention allows the modular design of a multi-way or single-way connection structure. It is suitable for pipe sheets of different materials and specifications, is suitable for a variety of application scenarios, and improves the versatility of the product.

The mold of the invention is fast and efficient for production of the V-shaped airtight sheet. The V-shaped airtight sheet produced is flat and shaped, it is not easy to occur wrinkles or inadequate welding adhesion during welding, and the airtight sheet welded on the pipe body sheet is flat and firm and has a good air-tightness.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a perspective view of an inflatable tent air columns of the invention;

FIG. 2 is one perspective view of two air columns in a bending connection of the invention;

FIG. 3 is a perspective view showing an embodiment of two pipe body sheets in a bending connection of the invention;

FIG. 4 is a perspective view showing a four-way structure of four air columns connected of the invention;

FIG. 5 is a perspective view showing a state of four body sheets after being connected and awaiting the welding of reinforcing sheets;

FIG. 6 is a sectional view showing an embodiment of the air column connection structure of the invention;

FIG. 7 is a sectional view showing another embodiment of the air column connection structure of the invention;

FIG. 8 is a sectional view showing a third embodiment of the air column connection structure of the invention;

FIG. 9 is a perspective view of two pipe body sheets connected and formed of the invention;

FIG. 10 is a perspective view of a pipe body sheet connected to an airtight sheet of the invention;

FIG. 11 is a perspective view of one embodiment of the V-shaped airtight sheet of the invention;

FIG. 12 is a perspective view of another embodiment of the V-shaped airtight sheet of the invention;

FIG. 13 is a perspective view of the V-shaped airtight sheet welded between two pipe body sheets;

FIG. 14 is an enlarged view of part K of FIG. 13;

FIG. 15 is a process diagram of an air column connection structure formed by a one-piece elongated pipe sheet;

FIG. 16 is an expanded view of a pipe body sheet with punched edges and notches;

FIG. 17 is a first schematic view showing the stacked relationship of the pipe body sheets;

FIG. 18 is a schematic view of a process of an air column connection structure;

FIG. 19 is a perspective view of the central hole;

FIG. 20 is a second schematic view showing the stacked relationship of the pipe body sheets;

FIG. 21 is a schematic view of an embodiment 1 of an end sealing structure;

FIG. 22 is a schematic view of an embodiment 2 of an end sealing structure;

FIG. 23 is a schematic view of an embodiment 3 of an end sealing structure;

FIG. 24 is a schematic view of an embodiment 4 of an end sealing structure;

FIG. 25 is a schematic view of an embodiment 5 of an end sealing structure;

FIG. 26 is a first perspective view showing an air column connection structure welded a reinforcing sheet and a sealing liner;

FIG. 27 is a second perspective view showing an air column connection structure welded reinforcing sheets and a sealing liner;

FIG. 28 is a schematic view showing a process of a four-way air column connection structure equipped with reinforcing sheets and a sealing liner;

FIG. 29 is a perspective view of mold closing and positioning of the mold for producing a V-shaped airtight sheet;

FIG. 30 is an exploded view of the mold for producing the V-shaped airtight sheet;

FIG. 31 is a sectional view of mold closing and positioning of the mold for producing a V-shaped airtight sheet;

FIG. 32 is a sectional view of mold closing and shaping of the mold for producing a V-shaped airtight sheet; and

FIG. 33 is a schematic view showing changes of a flat airtight sheet during the process of closing the mold.

DETAILED DESCRIPTION OF THE INVENTION

The invention will be described in further detail with specific embodiments.

As shown in FIGS. 1-10, an inflatable tent air column connection structure, comprising at least two pipe bodies 1 in communication with each other, a connection area of adjacent pipe bodies 1 is provided with a first welding area 11 for sealing and connecting the both, and the first welding area 11 is provided with an airtight sheet 2 covering the connection area of adjacent pipe bodies to form a double-layer structure as shown in FIG. 6. The airtight sheet 2 covers the connection area of the two pipe bodies 1 to prevent air leakage caused by the pipe bodies not being connected well, which serves as a double-insurance function.

Preferably, the airtight sheet 2 covers the first welding area 11 of the pipe body 1, and serves as a secondary safeguard to prevent air leakage from the air column if the air leakage occurs due to excessive welding or insufficient welding strength in the first welding area 11.

In order not to affect the texture of the air column pipe body 1 itself, the airtight sheet 2 is preferably made of a flexible material. The material is a stretchable soft film material, preferably material such as PVC, TPU, mesh-reinforced material and EVA, etc., which can maintain good air tightness after welding.

In a preferred embodiment of the connection structure of the invention, the first welding area 11 is provided a reinforcing sheet 3 configured to cover the connection area of adjacent pipes so as to provide additional structural support, further improve the tear resistance of the pipes joint and prevent leakage due to failure of the weld. The reinforcing sheet 3 may be provided on a side of the airtight sheet 2 of the pipe body sheet 10 to form a three-layer structure as shown in FIG. 7, or may be provided on the other side of the pipe body sheet 10 to form a three-layer structure as shown in FIG. 8.

When there are multiple interconnected pipe bodies 1, a convergence center of the multiple first welding areas 11 is provided with a central airtight patch 4 and/or a central reinforcing patch 31 to cover the convergence center, so as to improve the connection strength and sealing performance of the plurality of air columns and prevent the air column connection from cracking. It is preferable that the size of the central airtight patch 4 is larger than the size of the central reinforcing patch 31.

The pipe body 1, the reinforcing sheet 3 and the central reinforcing patch 31 are generally made of a kind of mesh-reinforced airtight material, preferably a mesh-reinforced coating material, which resists tearing and prevents air leakage. An innermost layer and an outermost layer thereof are both coating, and are generally made of PVC (polyvinyl chloride), TPU (thermoplastic polyurethane) or other polymer materials. The coating may be conveniently welded by hot melt bonding, with an intermediate layer being provided with a cloth or mesh layer (e. g., a fibrous or woven mesh) to improve stretch resistance, durability and stability of the pipe body.

Each pipe body of the invention includes a pipe body sheet and is rolled from a pipe body sheet 10, and the two long sides of the pipe body sheet 10 are respectively provided with a second welding area 13 for sealing and connecting the both.

An embodiment of an airtight sheet in the connection structure of the invention, and as shown in FIGS. 9 and 10. The airtight sheet 2 is a single sheet matched with the shape of the first welding area 11. The first welding area 11 of each pipe body 1 is provided with the airtight sheet 2. The airtight sheet 2 extends to the outside of the pipe body sheet 10. After the welding, the airtight sheets 2 of adjacent pipe bodies 1 are connected in an airtight manner, covering the connection areas of the adjacent pipe bodies 1.

As shown in FIGS. 11-14, another embodiment of an airtight sheet in the connection structure of the invention, the airtight sheet 2 formed as an integrated V-shaped sheet, and two sides 22 of the V-shaped sheet are respectively connected to the first welding areas 11 of adjacent pipe bodies 1 in an airtight manner, so that a middle bottom groove 21 of the V-shaped sheet maintains the integrity of the original sheet and covers the connection area of the adjacent pipe bodies 1, and the gas leakproofness is not affected by the welding quality. Meanwhile, the welding process or welding area is reduced.

In the invention, among the pipe body sheets 10, between the airtight sheet 2 and the pipe body sheets 10, and between the reinforcement sheet 3 and the airtight sheet 2 or the pipe body sheet 10, the connections are preferably achieved by high-frequency welding.

The method for manufacturing connection structure for air columns of the invention, comprising:

• • S1, cutting and shaping the pipe body sheet 10, and cutting an edge 12 in the pipe body sheet 10, the edge 12 has a shape consistent with the shape of the first welding area 11;
  • S2, covering the first welding area 11 of each pipe body sheet 10 with the airtight sheet 2, the shape of the airtight sheet 2 preferably matches the shape of the first welding area 11; and
  • S3, aligning and overlaying two pipe body sheets 10 covered with the airtight sheets 2, while maintaining separation between the airtight sheets 2, and then welding the two pipe body sheets 10 so that while the two pipe body sheets 10 are being welded, the two airtight sheets 2 are hermetically connected, covering the connection area of adjacent air columns.

In an embodiment of the step S2, the airtight sheet 2 is welded at the first welding area 11 at one side of each pipe body sheet 10, and the welded airtight sheet 2 extends beyond the edge 12 of the pipe body sheet 10, facilitating the subsequent welding of the pipe body sheets 10 while simultaneously welding the portion of the airtight sheets 2 that lie outsides the edges 12. In the subsequent step S3 of the present embodiment, the pipe body sheets 10 welded with the airtight sheets 2 are aligned face to face and stacked, with the airtight sheets 2 spaced apart on the upper and lower surfaces of the superimposed sheets, respectively, as shown in FIGS. 9 and 10.

In another embodiment of step S2, as shown in FIGS. 11-14, the airtight sheet 2 is V-shaped and is placed between adjacent pipe body sheets 10. The connecting edge of the V-shaped airtight sheet 2 is on the same side as the connecting end of the adjacent pipe body sheets 10. The both sides of the V-shaped airtight sheet 2 respectively cover the first welding areas 11 of the corresponding pipe body sheets 10. In the subsequent step S3, a separation plate is placed between the both sides of the V-shaped airtight sheet 2 so as to prevent the two sides of the V-shaped airtight sheet from being welded together during welding. The V-shaped airtight sheet reduces the probability of gas leakage of welding of two separate airtight sheets, and the V-shaped airtight sheet can be formed in one step, which is beneficial to the cost control in the production process. Alternatively, the connecting end of the overlapped pipe body sheets may be placed between the both sides of the V-shaped airtight sheet 2, allowing for welding without the need for a separation plate.

A further embodiment of the method of the invention further includes the steps of:

• • S4, providing a reinforcing sheet 3 covering the connection area of the adjacent pipe body sheets 10 on the connected airtight sheets 2, or providing a reinforcing sheet 3 covering the connection area of the pipe body sheets 10 on the other side of the connected pipe body sheets 10;
  • S5, welding each pipe body sheet 10 along both axial sides to form a pipe body 1.

In the step S4, reinforcing sheets 3 may be provided on both sides of the pipe body sheets 10. The reinforcing sheet 3 is welded to the first welding area 11, thereby effectively enhancing the tensile strength and torsional resistance of the connection area.

The welding method in the invention may be thermocompression welding or ultrasonic welding, with high-frequency welding being preferred as it allows for easier control of the welding quality.

When the air column connection structure is a two-air column connection structure, such as a two-way connection structure 100, the manufacturing method thereof is the above-mentioned method. It is also possible to form two pipe body sheets 10 by folding a elongated pipe sheet 101 in half along the width direction thereof, as shown in FIG. 15, so as to form integral connection. At this stage, step S1 involves punching a hole in the middle position of the elongated pipe sheet 101 to ensure that the connection portion in the middle of the elongated pipe sheet 101 is not cut off, thereby preserving the integrity and stability of the overall structure. Additionally, the production process can be further simplified and the production efficiency can be improved.

When the air column connection structure is a plurality of air columns sequentially connected in pairs, such as the four-way connection structure 200, in order to overcome the problems of easy tearing and air leakage caused by structural weakness at the top center and bottom center portions of the multi-way pipe connector and to enhance the sealing performance and mechanical strength at the portion, one or both of the central airtight patch 4 and the central reinforcing patch 31 may be welded at the convergence center of the multiple air column pipe bodies 1. This step is performed after the step S4 and/or after the step S5. The central airtight patch 4 and the central reinforcing patch 31 may be welded inside the pipe body or outside the pipe body, or both inside and outside the pipe body. The shapes of the first welding areas 11 connecting one air column to one air column and connecting two air columns are different.

In an embodiment in which a plurality of pipe bodies 1 are butted together to form a multi way connector, both a top center and a bottom center of the multi-way joint (such as a four-way connection structure 200) are respectively provided a central hole la. A central airtight patch 4 and a central reinforcing patch 31 are respectively welded to covered the inner and outer sides of the periphery of the central hole 1a,. In one embodiment of the multi-way pipe connector, the central airtight patch 4 is welded to the inner side of the periphery of the central hole 1a, and the central reinforcing patch 31 is welded to the outer side. This combined structure of double-sided welding firmly seals the periphery of the central hole 1a by means of inner and outer clamping. The size of the central airtight patch 4 is designed to be larger than that of the central reinforcing patch 31, both of which exceed the diameter of the central hole 1a, and the distribution of such a size gradient ensures a higher stress dispersion capacity in the welding area and prevents the welding point from tearing or failing due to localized excessive load. As shown in FIGS. 16-19, the manufacturing method of this embodiment includes the steps of:

• • S1, punching one end of the pipe body sheets 10 to form arc-shaped edges 12 and notches 14, wherein the edges 12 is provided in parallel at the end of each of the pipe body sheets 10, and the notches 14 are respectively provided between two corners and the two edges 12 of the end of each pipe body sheet 10;
  • S2, folding the pipe body sheets 10 in half along the length direction;
  • S3, successively stacking the pipe body sheets 10 folded in half, with their edges 12 and the notches 14 aligned;
  • S4, welding the adjacent pipe body sheets 10 along the edges 12 to form the first welding area 11;
  • S5, sequentially unfolding each pipe body sheet 10, and welding a reinforcing sheet 3 at each first welding area 11;
  • S6, welding two long side edges of each pipe body sheet 10 to form a pipe body 1, wherein the welding position thereof is a second welding area 13; a multi-way pipe connector is formed in all; and all notches 14 are abutted to form the central holes la of the multi-way pipe connector; and
  • S7, placing the central airtight patch 4 inside the central hole 1a, placing the central reinforcing patch 31 outside the central hole 1a, and welding the central airtight patch 4, the periphery of the central hole la and the central reinforcing patch 31 together, with the welding position thereof being the third welding area 15;

Herein, the order of steps S1 and S2 may be interchanged.

After the welding of the first welding areas 11 in the step S4 is completed, the adjacent pipe body sheets are connected to form an integrated whole. As shown in FIG. 17, four pipe body sheets 10 are butted such that the edges of port B and port C are aligned and welded together, the edges of port D and port E are aligned and welded together, the edges of port F and port G are aligned and welded together, and the edges of port H and port A are aligned and welded together.

The central airtight patch 4 and the central reinforcing patch 31 are sealedly connected to the periphery of the central hole la by the third welding area 15. This sealed connection firmly fuses the inner and outer materials so that the stress concentration can be effectively distributed after welding, further reducing the risk of cracking or falling off of the welding area due to long-term use or changes in the external environment (e. g., pressure fluctuations, mechanical shock, etc.).

This double-sided welding design not only effectively improves the sealing performance of the central hole la, but also significantly enhances the structural strength of the overall multi-way pipe connector. The welding process of the invention simplifies the manufacturing process, making the overall process more efficient. And, the quality of the welded product is more stable, with excellent anti-fatigue performance and long-term sealing ability, thus meeting the actual needs of high sealing and high reliability of air column products such as air tents.

The welding method of the invention is simple in steps and avoids the complex positioning and adjustment problems of conventional welding techniques. In this way, the efficiency of punching and welding is significantly improved by folding in half and stacking in multiple layers. The welding process of the invention requires less machining precision, can significantly reduce production costs. Also, material savings are achieved by the reasonable structure design and material use. The formed air column welding structure has excellent sealing performance and strength, can effectively avoid air leakage problems, and improve the reliability and service life of the product.

Of course, the plurality of pipe bodies 1 may be butted without the central holes la. As shown in FIG. 20, only two juxtaposed edges 12 are punched at each pipe body sheet 10, the two edges 12 are connected at one end, and then the pipe body sheets 10 are stacked so that each edge 12 is aligned with one edge 12 of adjacent pipe body sheet 10, The adjacent pipe body sheets 10 are sequentially welded to form the first welding areas 11. Alternatively, the central airtight patch 4 and/or the center reinforcing sheet 31 may be welded at the top center or the bottom center of the butted plurality of pipe body sheets 1 before and after the pipe bodies 1 are formed. For the multi-way structure without the central holes la, the same reinforcing sheet 3 can be used to connect the opposing first welding areas 11, securely bonding them together to improve the rigidity and durability of the overall structure.

Furthermore, as shown in FIG. 1, the air column connection structure of the invention in an air column structure of an inflatable tent, when the other end of the pipe body 1 is free to be connected to another pipe body, the free end of the pipe body is provided with an end sealing structure.

With regard to an embodiment 1 of the end sealing structure, as shown in FIG. 21, the end sealing structure includes an outer flange 16 provided at the free end of the pipe body 1. A sealing piece 41 and a bottom-closing sheet 32 are successively provided below the outer flange 16. The outer flange 16, a periphery of the sealing piece 41 and a periphery of the bottom-closing sheet 32 are welded together to form a fourth welding area 17. The material of the sealing piece 41 is the same as the material of the airtight sheet 2, and the material of the bottom-closing sheet 32 is the same as the material of the reinforcing sheet 3.

As shown in FIG. 22, an embodiment 2 of the end sealing structure, which differs from the embodiment 1 in that a rigid plate 7 is further sandwiched between a central portion of the bottom-closing sheet 32 and a central portion of the sealing piece 41, a fifth welding area 71 enclosing the rigid plate 7 is provided between the bottom-closing sheet 32 and the sealing piece 41, and the pipe body 1+the sealing piece 41+the bottom-closing sheet 32 are welded to form a sealing structure. The rigid plate 7 is generally made of rigid plastic, metal or wood, and functions to provide additional structural support to limit the deformation of the base due to the expansion of air pressure, and prevent the bottom-closing sheet 32 from tearing under high pressure conditions. The addition of the rigid plate 7 not only improves the overall rigidity of the base structure, but also significantly enhances the compression resistance, so that the air column pipe body as a supporting foot is more stable and durable.

As shown in FIG. 23, an embodiment 3 of the end sealing structure, which differs from the embodiment 1 in that an inner pull sheet 33 is further added as a reinforcing structure. the inner pull sheet 33 is welded in the middle of the bottom-closing sheet 32, and the welding area is a sixth welding area 321. The outer ring of the inner pull sheet 33 is tensioned upwards and is welded to an inner side wall of the pipe body 1 supporting the air column, and the welding area is a seventh welding area 18. The inner pull sheet 33 is also preferably made of a mesh-reinforced coating material. The inner pull sheet 33+the sealing piece 41+the bottom-closing sheet 32 are welded together, then the inner pull sheet 33 and the inner wall of the supporting air column pipe body 1 are welded together, and finally the supporting air column pipe body 1+the sealing piece 41+the bottom-closing sheet 32 are welded together to form a sealing structure. The inner pull sheet 33 forms a reaction force by pulling the base structure inwards to restrict the excessive expansion of the bottom-closing sheet 32 at the time of inflation, to prevent the base from tearing due to excessive pressure, and to further improve the sealing performance and durability. The inner pull sheet 33 is also made of the mesh-reinforced coating material, and is welded with the supporting air column pipe body 1 to form a entire high-sealing structure.

As shown in FIG. 24, an embodiment 4 of the end sealing structure, which is different from the embodiment 3 in that the embodiment 4 combines the advantages of the embodiment 2 and the embodiment 3 by interposing the rigid plate 7 between the inner pull sheet 33 and the sealing piece 41. The rigid plate 7 is sandwiched between the middle portion of the bottom-closing sheet 32 and the middle potion of the sealing piece 41, the inner pull sheet 33 is further provided above the middle portion of the sealing piece 41. An eighth welding area 72 enclosing the rigid plate 7 is provided between the middle portion of the inner pull sheet 33, the middle portion of the sealing piece 41 and the middle portion of the bottom-closing sheet 32. an outer ring of the inner pull sheet 33 is pulled upwards and welded to the inner side wall of the supporting air column pipe body 1, and the welding area is a ninth welding area 181. Herein, the rigid plate 7 is placed between the inner pull sheet 33+the sealing piece 41 and the bottom-closing sheet 32 and welded together at peripheries thereof, and the supporting air column pipe body 1+the sealing piece 41+the bottom-closing sheet 32 are welded together to form a sealing structure. The rigid plate 7 serves to control the expansion and deformation of the bottom portion due to the air pressure, and to prevent the bottom-closing sheet 32 from being torn due to a large pressure. The inner pull sheet 33 further improves the tension distribution at the bottom. The distribution of the multiple welding areas greatly improves the compression resistance and tear resistance of the whole structure, and ensures the stability under high pressure.

As shown in FIG. 25, an embodiment 5 of the end sealing structure, which differs from the embodiment 1 in that the embodiment 5 adopts an inner flange 19. The end sealing structure includes the inner flange 19 provided at a lower end of the supporting air column pipe body 1. A bottom-closing sheet 32 and a sealing piece 41 are provided on the inner flange 19 in sequence. The inner flange 19, the periphery of the bottom-closing sheet 32 and the periphery of the sealing piece 41 are welded together to form a tenth welding area 190. Herein, the sealing piece 41 is at the innermost layer, the bottom-closing sheet 32 is located in the middle, the inner flange 19 of the supporting air column pipe body 1 is located at the outermost layer. The end of the supporting air column pipe body 1 is folded inwards naturally to form the inner flange 19. The three are welded together to form a sealing structure, which significantly enhances the tear resistance and sealing strength of the bottom.

In a further preferred embodiment of the invention, as shown in FIGS. 26-27, a sealing liner 8 is provided between the adjacent pipe bodies, and the sealing liner 8 includes the same number of sealing pipes 81 as the pipe bodies 1. Each of the sealing pipes 81 communicates with each other, and edge of each of the sealing pipes 81 is welded to the inner wall of the corresponding pipe body 1. The arrangement of the sealing liner ensures that gas does not leak when passing through the connection structure of the plurality of pipe bodies 1, enhancing the sealing performance, safety and reliability of the entire system. The sealing liner 8 is made of the same stretchable flexible film material as that of the airtight sheet 2, so as to ensure that a good sealing state can be maintained under various operating conditions.

The step of forming the sealing liner 8 can be carried out by a method for producing a two-way connection structure 100 without the airtight sheet and the reinforcing sheet and a method for producing a four-way connection structure 200 without the airtight sheet, the reinforcing sheet and the central hole, except that the sheet material is replaced with the material of the sealing pipe sheet, as shown in FIG. 28.

When the sealing liner 8 is provided in the prepared air column connection structure, the sealing liner 8 is inserted into a two-way connection structure 100 or a four-way connection structure 200, and a free end edge of each sealing pipe 81 of the sealing liner 8 is welded to the inner wall of the corresponding pipe body 1 in the connection structure to form a liner welding area 82.

As shown in FIGS. 29-33, a mold for the above-mentioned inflatable tent air column connection structure, the mold is used for producing the V-shaped airtight sheet 2, including a lower mold 5 and an upper mold 6 which is configured to ascend and descend. The lower mold 5 is provided with a cambered surface 51 having a shape consistent with the edge 12 of the connecting end of the pipe body sheet 10. Both sides of the cambered surface 51 are respectively provided with an angled mold surface 52 matching the shape of the connecting end edge 12 of the pipe body sheet 10. The cambered surface 51 and the angled mold surface 52 correspond to the bottom groove 21 and both sides 22 of the V-shaped airtight sheet 2. The upper mold 6 includes a positioning module 61 abutting against the cambered surface 51 of the lower mold 5. An abutting surface of the positioning module 61 is matched with the cambered surface 51. Both sides of the positioning module 61 are respectively provided with an upper side module configured to be liftable elastically. The mold surfaces of the two upper side modules 62 are opposite to each other and can match and close with the two angled mold surfaces 52 of the lower mold 5 respectively.

A preferred embodiment of the mold of the invention, the positioning module 61 is provided with an upper mold base 60 configured to ascend and descend elastically, and the two upper side modules 62 are both connected to the upper mold base 60. The upper mold base 60 drives the lifting and lowering together, so as to ensure the synchronism of the two upper side modules 62 closing mold with the angled mold surface 52. The elastic rise and fall in the mold is preferably achieved through the deformation of elastic member such as spring 63. It is preferable that at least two springs 63 are provided between the positioning module 61 and the upper mold base 60 to prevent the unstable quality of closing mold caused by the unstable lifting of the upper side modules 62.

When the V-shaped airtight sheet 2 of the invention is formed between the lower mold 5 and the upper mold 6, a flat sheet is positioned and clamped by the upper mold 6 and the lower mold 5 to form an arc shape, then two upper side modules 62 close with the angled mold surface 52 of the lower mold 5, and the sheet material on both sides of the arc surface 51 are pressed down to form the V-shaped airtight sheet 2. The V-shaped airtight sheet produced by the mold of the invention is flat and stable in shape, facilitating its welding to the pipe body sheet 10.