Inflatable shaft for paper tube packaging

Abstract

The utility model provides a kind of paper tube packaging air inflation shaft, including a kind of paper tube packaging air inflation shaft, including shaft body, the shaft head of fixed connection in the both ends of shaft body, set in the inflation port of shaft body end, the shaft end step block of setting in the inside of shaft body, the air bag of setting in the inside of shaft body by the sliding restriction of ladder ring, the inflation port is connected with air bag inflation port by gas guide tube, it is characterized by: the shaft body is equipped with several key grooves, the size of key groove is slightly greater than the size of connecting key, connecting key is fixedly connected by the shaft body and expansion plate with the shaft body inside through key groove, the expansion plate camber is identical with shaft body, and hexagonal recess is opened in expansion plate. The technical scheme can eliminate the bulging effect caused by uneven pressure of traditional air inflation shaft, without leaving any pressure mark or edge mark in paper tube inner wall, and improve the cleanliness of paper tube packaging.

Description

Technical Field

[0001] This utility model relates to the field of paper tube packaging, and in particular to an air shaft for paper tube packaging. Background Technology

[0002] In the automated packaging, slitting, rewinding, and transportation and storage of paper tubes, the air shaft, as a core winding and positioning component, directly determines production efficiency, material loss rate, and the quality of the final product. Traditional air shafts inflate air chambers to push external expansion plates radially to lock the paper tube. However, traditional smooth expansion plates are prone to excessive bulging in the middle during inflation, or uneven stress on the paper tube, resulting in indentations on the inner wall. This not only damages the paper tube but may also cause wrinkles, deformation, and other quality defects in the sensitive winding material wrapped above. Furthermore, the large-area friction between the traditional smooth expansion plate and the paper tube generates dust particles, polluting the clean environment. Gaps and sharp edges on the equipment surface can easily trap contaminants, creating cleaning dead zones and making it difficult to meet the hygiene standards of cleanroom production. Utility Model Content

[0003] To achieve the above objectives, the present invention adopts the following technical solution: A pneumatic shaft for paper tube packaging includes a shaft body, shaft heads fixedly connected to both ends of the shaft body, an inflation port located at the end of the shaft body, a stepped block located inside the shaft body, and an air bladder located inside the shaft body with sliding restricted by a stepped ring. The inflation port is connected to the air bladder inflation port through an air guide pipe. The shaft body is characterized by having several keyways, the size of which is slightly larger than the size of the connecting key. The connecting key passes through the keyways from inside the shaft body and is fixedly connected to an expansion plate. The curvature of the expansion plate is consistent with that of the shaft body, and a hexagonal groove is carved on the expansion plate.

[0004] Preferably, the hexagonal groove is a regular hexagonal groove.

[0005] Preferably, the depth of the hexagonal groove is 0.2~0.5mm.

[0006] Preferably, the width of the hexagonal groove is 1.5~3mm.

[0007] Preferably, the side length of the hexagonal groove is 0.9~1.7mm.

[0008] Preferably, the edges of the expansion plate and the hexagonal groove are rounded and have smooth surfaces.

[0009] Preferably, the expansion plate is provided with 4 to 12 plates.

[0010] Compared with the prior art, the beneficial effects of this utility model are: it eliminates the bulging effect caused by uneven pressure in traditional air shafts, does not leave any indentations or curling marks on the inner wall of the paper tube, and improves the cleanliness of paper tube packaging. Attached Figure Description

[0011] Figure 1 This is an external front view schematic diagram of Embodiment 1 of this utility model; Figure 2 This is a cross-sectional view of Embodiment 1 of the present invention; Figure 3 This is a cross-sectional view of the airbag in embodiment 1 of this utility model when it is not inflated; Figure 4 This is a cross-sectional view of the airbag inflated according to Embodiment 1 of this utility model; Figure 5 This is a partial enlarged view of the connecting part in Embodiment 1 of this utility model; Labeling explanation: 1-Shaft head; 2-Inflation port; 3-Expansion plate; 31-Hexagonal groove; 4-Shaft body; 41-Shaft end stepped block; 42-Air bladder; 43-Connecting key; 5-Keyway. Detailed Implementation

[0012] To enable those skilled in the art to better understand the present application, the technical solutions in the embodiments of the present application will be clearly and completely described below with reference to the accompanying drawings. A pneumatic shaft for paper tube packaging includes a shaft body 4, shaft ends 1 fixedly connected to both ends of the shaft body, an inflation port 2 disposed at the end of the shaft body 4, a shaft end stepped block 41 disposed inside the shaft body, and an air bladder 42 disposed inside the shaft body 4 and restricted from sliding by the stepped ring 41. The inflation port 2 is connected to the air bladder inflation port 21 through an air guide pipe. The shaft body 4 is characterized by having several keyways 5, the size of which is slightly larger than the size of a connecting key 43. The connecting key 43 passes through the keyways inside the shaft body and is fixedly connected to an expansion plate 3. The curvature of the expansion plate 3 is consistent with that of the shaft body, and a hexagonal groove 31 is carved on the expansion plate 3.

[0013] The hexagonal grooves 31 form a network on the surface of the expansion plate 3, which can quickly equalize the pressure when the airbag inflates and pushes the expansion plate 3. This transforms the traditional large-area surface contact into a composite contact mode of raised frame rigid support points and flexible groove cavities, eliminating local pressure concentration and ensuring that the displacement and pressure height of the expansion plate 3 along the axial direction are consistent. This provides a uniform tension force for the paper tube and eliminates the bulging effect caused by uneven pressure in traditional air shafts. It will not leave any indentations or curling marks on the inner wall of the paper tube. At the same time, the actual contact area with the inner wall of the paper tube is greatly reduced. During inflation and deflation, especially during deflation and unloading of the paper tube, and during high-speed rotation, the number of frictional dust and particles generated is greatly reduced, significantly reducing the particulate matter generated by the friction between the paper tube and the equipment, and improving cleanliness.

[0014] Combination Figure 3 , Figure 4This describes the specific operation of the air shaft. When the air bladder 42 of the air shaft is not inflated... Figure 3 In the initial state, the expansion plate 3 is not lifted, and its overall diameter is relatively small. Inflation causes the air bladder 42 to expand, lifting the surrounding connecting key 43. The connecting key 43 moves outward through the keyway 5, lifting the expansion plate 3. As the expansion plate 3 rises, the diameter of the air shaft increases, thus securing the paper tube. During deflation, gas flows out from the air hole 21, the air bladder 42 returns to its original size, the connecting key 43 naturally retracts, the expansion plate 3 retracts along with the connecting key 43, the air shaft returns to its original diameter, and the paper tube is released.

[0015] Preferably, the hexagonal groove 31 is a regular hexagonal groove.

[0016] When the airbag is inflated, the regular hexagonal grooves on the expansion plate will form regular and symmetrical interlocking points on the inner wall of the paper tube. The force at each interlocking point is consistent in magnitude and direction, which can further avoid local stress concentration caused by uneven groove side lengths and angles. It is especially suitable for thin paper tubes and can effectively reduce the risk of paper tube breakage and wrinkling.

[0017] Preferably, the depth of the hexagonal groove 31 is 0.2~0.5mm.

[0018] By strictly limiting the groove depth to within 0.5mm, only the very surface material is removed, which has a negligible impact on the overall structural rigidity and bending strength of the expansion plate 3. It can still maintain its shape under high pressure and will not destroy the pressure equalization effect due to its own deformation.

[0019] Preferably, the width of the hexagonal groove 31 is 1.5~3mm.

[0020] Preferably, the side length of the hexagonal groove 31 is 0.9~1.7mm.

[0021] The width and side length determine the density and shape of the honeycomb network, which together determine the area ratio of the raised support surface and the recessed pressure equalization cavity. This ensures sufficient support area to guarantee gripping force and prevent point crushing of the inner wall of the paper tube, while providing sufficient pressure equalization cavity area to provide excellent pressure equalization and buffering capacity.

[0022] Preferably, the edges of the expansion plate 3 and the hexagonal groove 31 are rounded and have smooth surfaces.

[0023] This avoids leaving microscopic scratches or crush points on the inner wall of the paper tube, further protecting the structural integrity of the paper tube. The smooth, rounded surface has no dead corners or adhesion points, so whether it is compressed air blowing or liquid wiping, contaminants cannot stay here and can be easily and thoroughly removed, further improving cleanliness.

[0024] Preferably, the expansion plate 3 is provided with 4 to 12 pieces.

[0025] The above description is merely a preferred embodiment of this application and is not intended to limit this application. Various modifications and variations can be made to this application by those skilled in the art. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of this application should be included within the protection scope of this application.

Claims

1. A pneumatic shaft for paper tube packaging, comprising a shaft body (4), shaft ends (1) fixedly connected to both ends of the shaft body, an inflation port (2) disposed at the end of the shaft body (4), a shaft end stepped block (41) disposed inside the shaft body, and an air bladder (42) disposed inside the shaft body (4) and restricted from sliding by the stepped block (41), wherein the inflation port (2) is connected to the air bladder inflation port (21) through an air guide tube, characterized in that: The shaft (4) has several keyways (5), the size of which is slightly larger than that of the connecting key (43). The connecting key (43) passes through the keyway from the shaft and is fixedly connected to the expansion plate (3). The curvature of the expansion plate (3) is consistent with that of the shaft, and a hexagonal groove (31) is chiseled on the expansion plate (3).

2. The air shaft for paper tube packaging as described in claim 1, characterized in that: The hexagonal groove (31) is a regular hexagonal groove.

3. The air shaft for paper tube packaging as described in claim 1, characterized in that: The depth of the hexagonal groove (31) is 0.2~0.5mm.

4. The air shaft for paper tube packaging as described in claim 1, characterized in that: The width of the hexagonal groove (31) is 1.5~3mm.

5. The air shaft for paper tube packaging as described in claim 1, characterized in that: The hexagonal groove (31) has a side length of 0.9~1.7mm.

6. The air shaft for paper tube packaging as described in claim 1, characterized in that: The edges of the expansion plate (3) and the hexagonal groove (31) are rounded and have smooth surfaces.

7. The air shaft for paper tube packaging as described in claim 1, characterized in that: The expansion plate (3) is provided with 4 to 12.

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