An integral airtight capsule structure

Abstract

The present invention discloses an integral airtight capsule structure, belonging to the technical field of near-Earth space manned flight, interplanetary manned flight and on-orbit residence. The airtight capsule structure comprises: a flexible skin and a rigid plugging cover; the flexible skin is foldable, and after unfolding, it is a hollow columnar structure, and circular notches are processed at both ends of the hollow columnar structure, and a rigid plugging cover is installed on each circular notch, and the rigid plugging cover closes the circular notch. The present invention can meet the high reliability requirements of the airtight layer, the uniform force of the bearing layer, and the tight connection between the airtight layer and the rigid plugging cover.

Description

Technical Field

[0001] The present invention belongs to the technical field of near-Earth space manned and interplanetary manned flight and on-orbit residence, and in particular relates to an integral airtight capsule structure. Background Art

[0002] Whether it is manned flight and on-orbit stay in near-Earth space, or manned voyage between planets or even stars, a reliable sealed environment is required for the crew - a sealed cabin, which is a necessary resource for human extraterrestrial activities. At present, the sealed cabins in orbit are mainly rigid metal cabins, and flexible inflatable and deployable sealed cabins have not yet been tested in orbit in my country.

[0003] Patent US6547189B1 "INFLATABLE VESSEL AND METHOD" (Robert P. Swiatek) invented an inflatable sealed cabin structure with a rigid column in the middle for use in space. The skin structure is composed of an anti-wear layer, an airtight composite layer, a constraint layer, a space debris protection layer, and a thermal protection layer from the inside to the outside. The connection between the layers determines the specific performance of the sealed cabin and also reflects the reliability design of the seal. However, there is no description of the connection between the layers and the analysis of specific performance indicators in this patent.

[0004] Patent CN201020653920.0 "Inflatable Sealing Structure of an Expansion Cabin" (Tan Shulin, Zhang Ruixiao) provides an inflatable sealing structure for an expansion cabin, which seals the expansion cabin mainly by inflating an inflatable sealing strip to make it expand and seal the gap between two adjacent cabin wall panels. When the sealing strip is not inflated or the inflation pressure is insufficient, the sealing function cannot be achieved for the expansion cabin, and this structure is for the sealing of the expansion cabin and does not involve the design of an integral airtight bladder structure.

[0005] The document “Structural Design and Analysis of Inflatable Space Deployable Cabins” (Master’s thesis of Northeastern University, author: Chen Keli) studied the inflatable space deployable cabins - central core column structure design, multi-layer flexible shell design, inflation system design, etc., but did not involve the specific structural design parameters, performance indicators, rigid-flexible connections, sealing reliability and other related contents of the airtight layer and pressure-bearing layer. Summary of the invention

[0006] In view of this, the present invention provides an integral airtight bladder structure that can meet the high reliability requirements of the airtight layer, uniform force on the load-bearing layer, and tight connection between the airtight layer and the rigid plugging cover.

[0007] The present invention is achieved through the following technical solutions:

[0008] An integral airtight bladder structure comprises: a flexible skin and a rigid plugging cover; the flexible skin is foldable and becomes a hollow columnar structure when unfolded, circular notches are processed at both ends of the hollow columnar structure, a rigid plugging cover is installed on each circular notch, and the rigid plugging cover closes the circular notch.

[0009] Furthermore, the flexible skin is divided into, from the inside to the outside, an airtight layer, a pressure-bearing layer, a debris protection layer and a heat protection layer. The pressure-bearing layer is fixed to the outer surface of the airtight layer by bonding, the debris protection layer is fixed to the outer surface of the pressure-bearing layer by bonding or sewing, and the heat protection layer is fixed to the outer surface of the debris protection layer by bonding or sewing.

[0010] Furthermore, the airtight layer is composed of two layers, namely a first airtight layer and a second airtight layer; the first airtight layer and the second airtight layer are compounded by adopting a circular or polygonal bonding technology, that is, the first airtight layer and the second airtight layer are compounded into an integrated structure by circular or polygonal hot pressing, adjacent circles or polygons are not connected, and the inside of the circles or polygons is vacuum, and the first airtight layer and the second airtight layer are compounded to form an airtight layer with a hollow columnar structure and circular notches at both ends consistent with the appearance of the flexible skin, and then the pressure-bearing layer, the debris protection layer and the heat protection layer are sequentially coated on the outside of the airtight layer to form a flexible skin.

[0011] Furthermore, the pressure-bearing layer adopts Kevlar braid, and the Kevlar braid is pre-stretched before braiding, that is, the Kevlar braid is coiled in a high and low temperature test box, and a weight of about kg is hung below, the temperature in the box is ℃, and the treatment time is hours; then, two widths of Kevlar braids are selected according to the different curvature radii of the flexible skin, one width of Kevlar braid is used as the axial braid of the pressure-bearing layer, and the other width of Kevlar braid is used as the annular braid of the pressure-bearing layer; the axial braid is cut and pre-sewn using a rigid plug as a positioning reference; the annular braid is adjusted for length consistency using ground tooling; finally, the axial braid and the annular braid are cross-woven, and GD silicone rubber is coated at the intersection of the axial braid and the annular braid to fix them, so as to finally form a pressure-bearing layer.

[0012] Furthermore, the rigid plugging cover adopts a metal structure; the two rigid plugging covers are fixed on the two circular notches of the flexible skin respectively through rigid-flexible connectors, and the circular notches are closed. The rigid-flexible connection between the rigid plugging cover and the flexible skin is as follows:

[0013] The rigid-flexible connector is an annular plate, and the outer edge of the upper surface of the annular plate is processed with an annular limiting boss coaxial with the annular plate. The lower surface of the rigid-flexible connector is fixed to the outer wall surface around the circular notch of the airtight layer by silicone rubber bonding and screws, and a sealing gasket is installed between the lower surface of the rigid-flexible connector and the outer wall surface of the airtight layer;

[0014] The pressure-bearing layer wrapped around the airtight layer extends out an annular reinforcement belt, and an annular steel ring is fixed at the end of the annular reinforcement belt. The steel ring is clamped on the inner circumference of the annular limiting boss on the upper surface of the rigid-flexible connector to achieve the connection between the pressure-bearing layer and the rigid-flexible connector;

[0015] The rigid plugging cover is installed on the rigid-flexible connector by screws and closes the circular gap of the airtight layer; and a sealing ring is installed between the contact surface of the rigid plugging cover and the rigid-flexible connector. When the rigid plugging cover is installed on the rigid-flexible connector, the rigid plugging cover presses the sealing ring.

[0016] Furthermore, the airtight layer is made of ethylene-vinyl alcohol copolymer EVOH material.

[0017] Beneficial effects:

[0018] (1) The present invention proposes an integral airtight bladder structure composed of a flexible skin and a rigid cover. The integral airtight bladder structure is one of the main configurations of an inflatable deployable sealed cabin. It has the advantages of light weight, small folded volume, high deployment reliability, low cost, and short development cycle. It is also conducive to the inflatable sealed cabin to achieve the purpose of maximizing volume, lightweight structure, and complex functions.

[0019] (2) The flexible skin of the present invention adopts a multifunctional skin material. The multifunctional skin structure is divided into an airtight layer, a pressure-bearing layer, a debris protection layer, and a heat protection layer from the inside to the outside according to its function. The airtight layer and the pressure-bearing layer are the main functional layers of the flexible skin. The airtight layer has the characteristics of high reliability and the pressure-bearing layer has uniform force.

[0020] (3) The airtight layer of the present invention is composed of two layers, namely a first airtight layer and a second airtight layer; the first airtight layer and the second airtight layer are compounded by adopting a circular or polygonal bonding technology, so that when the airtight layer is partially damaged, the leakage probability of the entire airtight bladder structure is greatly reduced, the redundancy of the airtight layer is increased, the airtightness of the overall structure is improved, the reliability of the overall structure is improved, and the weight increase of the overall structure does not exceed 0.1% of the total weight.

[0021] (4) The pressure-bearing layer of the present invention adopts Kevlar woven tape, so that the integral airtight bladder structure is evenly stressed, and the ratio of maximum stress to minimum stress does not exceed 1.1.

[0022] (5) The two rigid plugging covers of the present invention are fixed one by one on the two circular notches of the flexible skin, and the circular notches are closed. The pressure-bearing layer, the airtight layer and the rigid plugging covers form an airtight bag body with rigid-flexible connection, so that the leakage rate at the connection between the airtight layer and the rigid plugging cover, that is, the leakage rate of the integral airtight bag body structure, is not higher than the leakage rate of the airtight layer. BRIEF DESCRIPTION OF THE DRAWINGS

[0023] Figure 1 It is a structural composition diagram of the present invention;

[0024] Figure 2 It is the composition diagram of the flexible skin;

[0025] Figure 3 is a schematic diagram of the connection between the first airtight layer and the second airtight layer;

[0026] Figure 4 This is the weaving structure diagram of the pressure-bearing layer;

[0027] Figure 5 The diagram is a diagram of the rigid-flexible connection airtight structure of the flexible skin and the rigid plugging cover;

[0028] Figure 6 This is a diagram showing the relationship between the fundamental frequency and the pressure difference of the present invention;

[0029] Among them, 1-flexible skin, 2-rigid blocking cover, 3-first airtight layer, 4-second airtight layer, 5-pressure bearing layer, 6-debris protection layer, 7-thermal protection layer, 8-circular bonding, 9-airtight layer, 10-rigid-flexible connector, 11-screw A, 12-sealing gasket, 13-reinforcement belt, 14-steel ring, 15-screw B. DETAILED DESCRIPTION

[0030] The present invention is described in detail below with reference to the accompanying drawings and embodiments.

[0031] This embodiment provides an integral airtight capsule structure. Figure 1 , comprising: a flexible skin 1 and a rigid plugging cover 2; the flexible skin 1 is foldable, and after unfolding, it is a hollow columnar structure, and circular notches are processed at both ends of the hollow columnar structure, and a rigid plugging cover 2 is installed on each circular notch;

[0032] The rigid plugging cover 2 adopts a metal structure, and its sealing performance inherits the rigid metal cabin sealing technology, which facilitates the docking of the airtight bladder structure and the rigid metal cabin;

[0033] The flexible skin 1 is made of multifunctional skin material. Figure 2 The flexible skin 1 is divided into an airtight layer, a pressure-bearing layer 5, a debris protection layer 6 and a heat protection layer 7 from the inside to the outside. The pressure-bearing layer 5 is fixed to the outer surface of the airtight layer by bonding (i.e., local heat sealing), the debris protection layer 6 is fixed to the outer surface of the pressure-bearing layer 5 by bonding or sewing, and the heat protection layer 7 is fixed to the outer surface of the debris protection layer 6 by bonding or sewing; wherein the airtight layer and the pressure-bearing layer 5 are the main functional layers of the flexible skin 1;

[0034] The airtight layer 9 is composed of two layers, namely, a first airtight layer 3 and a second airtight layer 4; the first airtight layer 3 and the second airtight layer 4 are both made of ethylene-vinyl alcohol copolymer EVOH material, and in a vacuum environment (to avoid adding extra load to the bladder structure during on-track operation), the first airtight layer 3 and the second airtight layer 4 are compounded by circular or polygonal bonding technology, that is, the first airtight layer 3 and the second airtight layer 4 are compounded into an integral structure by circular or polygonal hot pressing, and adjacent circles or polygons are not connected to form a parallel space, as shown in the attached Figure 3 As shown, that is, space N, space N+1, space N+2, ..., and the inside of the circle or polygon is vacuum; the first airtight layer 3 and the second airtight layer 4 are combined to form an airtight layer 9 of a hollow columnar structure with circular notches processed at both ends consistent with the appearance of the flexible skin 1, and then the pressure-bearing layer 5, the debris protection layer 6 and the heat protection layer 7 are sequentially coated on the outside of the airtight layer 9 to be fixedly connected to form the flexible skin 1;

[0035] See attached Figure 4 , the pressure-bearing layer 5 adopts Kevlar braid, and the Kevlar braid is pre-stretched before braiding, that is, the Kevlar braid is coiled in a high and low temperature test box, and a weight of about 20 kg is hung below. The temperature in the box is 80°C and the treatment time is 24 hours; then, two widths of Kevlar braid are selected according to the different curvature radii of the flexible skin 1, one width of Kevlar braid is used as the axial braid of the pressure-bearing layer 5, and the other width of Kevlar braid is used as the circumferential braid of the pressure-bearing layer 5; the axial braid is cut and pre-sewn using the rigid plug cover 2 as a positioning reference; the length consistency of the circumferential braid is adjusted using the ground tooling; finally, the axial braid and the circumferential braid are cross-woven, and GD414 silicone rubber is coated at the intersection of the axial braid and the circumferential braid to fix it, and finally the pressure-bearing layer 5 is formed;

[0036] The debris protection layer 6 is made of basalt cloth, aramid cloth and polyurethane foam; the heat protection layer 7 is made of polyester mesh, and the inner and outer surfaces of the polyester mesh are coated with aluminum-plated polyester film for heat protection;

[0037] The two rigid plugging covers 2 are fixed to the two circular notches of the flexible skin 1 through the rigid-flexible connectors 10, and the circular notches are closed. Figure 5 , the rigid-flexible connection between the rigid plug cover 2 and the flexible skin 1 is as follows:

[0038] The rigid-flexible connector 10 is an annular plate, and the outer edge of the upper surface of the annular plate is processed with an annular limiting boss coaxial with it. The lower surface of the rigid-flexible connector 10 is fixed to the outer wall surface around the circular notch of the airtight layer 9 by silicone rubber bonding and screws A11, and a sealing gasket 12 is installed between the lower surface of the rigid-flexible connector 10 and the outer wall surface of the airtight layer 9;

[0039] The pressure-bearing layer 5 coated on the outside of the airtight layer 9 extends out an annular reinforcement belt 13, and an annular steel ring 14 is fixed at the end of the annular reinforcement belt 13. The steel ring 14 is clamped on the inner circumference of the annular limiting boss on the upper surface of the rigid-flexible connector 10 to achieve the connection between the pressure-bearing layer 5 and the rigid-flexible connector 10; wherein the reinforcement belt 13 is formed by belt rolling;

[0040] The rigid plugging cover 2 is installed on the rigid-flexible connector 10 by screws B15, and the circular notch of the airtight layer 9 is closed; and a sealing ring is installed between the contact surface of the rigid plugging cover 2 and the rigid-flexible connector 10. When the rigid plugging cover 2 is installed on the rigid-flexible connector 10, the rigid plugging cover 2 presses the sealing ring; finally, the pressure-bearing layer 5, the airtight layer 9 and the rigid plugging cover 2 form a rigid-flexible airtight capsule, and the gas permeability is <0.1Pam 3 / s.

[0041] Working principle: The airtightness and structural fundamental frequency of the integral airtight capsule structure are tested. A 20KPa (gauge pressure) helium and air mixture is filled into the airtight capsule structure and placed in a vacuum tank. The tank is evacuated to 10 -1 Pa, turn on the helium mass spectrometer leak detector, and test the airtightness (leakage rate) of the airtight capsule structure by collecting the helium concentration in the vacuum tank. The leakage rate of the integral airtight capsule structure is 0.08Pam 3 / s;

[0042] Fill the airtight bladder structure with 20KPa, 40KPa, 60KPa, and 80KPa (standard pressure) air. Fix the two ends of the airtight bladder structure with a bracket car to test the fundamental frequency of the overall airtight bladder structure. The fundamental frequency changes with the gauge pressure, such as Figure 6 As shown, it can be seen that the pressure-holding capacity of the airtight bladder structure is stable, and further it can be seen that the airtightness of the airtight bladder structure meets the requirements.

[0043] In summary, the above are only preferred embodiments of the present invention and are not intended to limit the protection scope of the present invention. Any modifications, equivalent substitutions, improvements, etc. made within the spirit and principles of the present invention should be included in the protection scope of the present invention.

Claims

1. An integral airtight capsule structure, characterized in that: include: Flexible skin and rigid plugging cover; the flexible skin is foldable and becomes a hollow columnar structure after unfolding, circular notches are processed at both ends of the hollow columnar structure, a rigid plugging cover is installed on each circular notch, and the rigid plugging cover closes the circular notch; The flexible skin is divided into an airtight layer, a pressure-bearing layer, a debris protection layer and a heat protection layer from the inside to the outside, the pressure-bearing layer is fixed to the outer surface of the airtight layer by bonding, the debris protection layer is fixed to the outer surface of the pressure-bearing layer by bonding or sewing, and the heat protection layer is fixed to the outer surface of the debris protection layer by bonding or sewing; The airtight layer is composed of two layers, namely, a first airtight layer and a second airtight layer; the first airtight layer and the second airtight layer are compounded by circular or polygonal bonding technology, that is, the first airtight layer and the second airtight layer are compounded into an integrated structure by circular or polygonal hot pressing, adjacent circles or polygons are not connected, and the inside of the circles or polygons is vacuum, the first airtight layer and the second airtight layer are compounded to form an airtight layer of a hollow columnar structure with circular notches processed at both ends consistent with the shape of the flexible skin, and then the pressure-bearing layer, the debris protection layer and the heat protection layer are sequentially coated on the outside of the airtight layer to be fixedly connected to form a flexible skin; The rigid plugging cover adopts a metal structure; the two rigid plugging covers are fixed on the two circular notches of the flexible skin respectively through rigid-flexible connectors, and the circular notches are closed. The rigid-flexible connection between the rigid plugging cover and the flexible skin is as follows: The rigid-flexible connector is an annular plate, and the outer edge of the upper surface of the annular plate is processed with an annular limiting boss coaxial with the annular plate. The lower surface of the rigid-flexible connector is fixed to the outer wall surface around the circular notch of the airtight layer by silicone rubber bonding and screws, and a sealing gasket is installed between the lower surface of the rigid-flexible connector and the outer wall surface of the airtight layer; The pressure-bearing layer wrapped around the airtight layer extends out an annular reinforcement belt, and an annular steel ring is fixed at the end of the annular reinforcement belt. The steel ring is clamped on the inner circumference of the annular limiting boss on the upper surface of the rigid-flexible connector to achieve the connection between the pressure-bearing layer and the rigid-flexible connector; The rigid plugging cover is installed on the rigid-flexible connector by screws and closes the circular gap of the airtight layer; and a sealing ring is installed between the contact surface of the rigid plugging cover and the rigid-flexible connector. When the rigid plugging cover is installed on the rigid-flexible connector, the rigid plugging cover presses the sealing ring.

2. An integral airtight bladder structure as claimed in claim 1, characterized in that: The pressure-bearing layer adopts Kevlar braid, and the Kevlar braid is pre-stretched before braiding, that is, the Kevlar braid is coiled in a high and low temperature test box, and a weight of about kg is hung below. The temperature in the box is ℃, and the treatment time is hours; then, two widths of Kevlar braids are selected according to the different curvature radii of the flexible skin, one width of Kevlar braid is used as the axial braid of the pressure-bearing layer, and the other width of Kevlar braid is used as the circumferential braid of the pressure-bearing layer; the axial braid is cut and pre-sewn using a rigid plug as a positioning reference; the circumferential braid is adjusted for length consistency using ground tooling; finally, the axial braid and the circumferential braid are cross-woven, and GD silicone rubber is coated at the intersection of the axial braid and the circumferential braid to fix them, so as to finally form a pressure-bearing layer.

3. An integral airtight bladder structure according to claim 1 or 2, characterized in that: The airtight layer is made of ethylene-vinyl alcohol copolymer EVOH material.

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