Connecting structure for ultrathin stainless steel storage box

Abstract

A connecting structure for an ultrathin stainless steel storage box comprises a box bottom, a short shell and a barrel section. The box bottom comprises a transition ring, a circular ring and a top cover flange, the transition ring and the circular ring are welded through a circumferential weld, and the circular ring and the top cover flange are welded through a circumferential weld; the transition ring comprises a plurality of bent arc plates and a plurality of reinforcing strips, the bent arc plates are welded and connected through longitudinal seams, and the longitudinal seams are reinforced through the reinforcing strips; a bottom locking structure is arranged in the bent arc plate, the bent arc plate is connected with the short shell through bottom locking welding, and the bent arc plate is connected with the cylinder section in a butt welding mode. The hard stainless steel plate is selected as the raw material, the performance of the transition ring is guaranteed, and the problem of low hot forging performance is avoided; the connecting face of the transition ring and the cylinder section is arranged at the position 100 mm away from the equatorial plane, and the problem of additional bending moment of a welding seam at the position is solved. Reinforcing strips are introduced into weak longitudinal joints of the transition ring, and the problem of performance degradation caused by welding joints is solved.

Description

Technical Field

[0001] The invention relates to a connection structure for an ultra-thin stainless steel tank, which is used for connecting a propellant tank structure of a space vehicle. Background Art

[0002] The propellant tank is a key component of the launch vehicle's power system and structural system. It plays the role of transmitting force, maintaining shape, storing and transporting propellants, etc. It accounts for about 50-60% of the weight of the rocket body structure, and has high requirements for lightness and reliability. The tank bottom structure is a key link in the tank structure. It is generally composed of a transition ring, a circular ring, and a top cover. Among them, the transition ring is one of the most critical structures of the entire tank. During the development of a certain type of rocket, the first-stage oxygen tank and the second-stage hydrogen tank were successively damaged by low pressure, which is closely related to the low performance of the transition ring. The transition ring is mainly used to connect the tank bottom 1, the barrel section 3, and the short shell 2 (or another barrel section).

[0003] At present, there are two main production paths for transition rings of aluminum alloy tanks, namely (1) O-state aluminum alloy integral ring rolling, heat treatment, and machining represented by the new generation 2219 aluminum alloy, and (2) profile milling, welding, and heat treatment represented by 2A14. The characteristics of the material determine that stainless steel tanks must innovate their structural forms. Unlike aluminum alloys that improve material properties through heat treatment, stainless steel mainly improves material properties through cold working hardening, which also makes it difficult to manufacture large forging rings by cold forging, difficult to meet strength requirements by hot forging, and low performance of hot drawn profiles. Stainless steel has high strength, which leads to thin tank walls, but thin walls further increase the difficulty of manufacturing stainless steel transition ring forgings and profiles. In addition, large forging rings are expensive and difficult to meet low-cost requirements.

[0004] In summary, there are some problems with the bottom transition ring of stainless steel storage tanks, mainly including the following points:

[0005] (1) The transition ring is a key structure of the tank, and its performance directly determines the reliability of the structure;

[0006] (2) It is difficult to produce forged rings for stainless steel tanks by aluminum alloy integral ring rolling or profile welding;

[0007] (3) Forging rings are expensive and cannot meet low-cost demands. Summary of the invention

[0008] The technical problem to be solved by the present invention is: to overcome the shortcomings of the prior art and provide an ultra-thin stainless steel connection structure with a high-performance and low-cost transition ring based on hard plate welding, that is, a connection structure for an ultra-thin stainless steel tank, which solves the problems of low performance, difficult manufacturing and high cost of stainless steel forging rings, and achieves the purposes of high performance and low cost of the stainless steel tank connection structure.

[0009] The purpose of the present invention is achieved through the following technical solutions:

[0010] A connection structure for an ultra-thin stainless steel storage tank, comprising a tank bottom, a short shell, and a cylinder section;

[0011] The bottom of the box includes a transition ring, a circular ring and a top cover flange. The transition ring is connected to the circular ring by a circular weld, and the circular ring is connected to the top cover flange by a circular weld. The transition ring includes a plurality of curved arc plates and a plurality of reinforcing strips. The plurality of curved arc plates are connected by longitudinal seam welding, and the longitudinal seams are reinforced by reinforcing strips.

[0012] A bottom locking structure is provided in the curved arc plate, the curved arc plate is connected to the short shell by bottom locking welding, and the curved arc plate is connected to the cylinder section by butt welding.

[0013] In one embodiment of the present invention, the connection portion between the curved arc plate and the barrel section is a structure of equal thickness.

[0014] In one embodiment of the present invention, the circular ring is made by welding melon segments or integrally forming them.

[0015] In one embodiment of the present invention, the top cover flange is manufactured by machining.

[0016] In one embodiment of the present invention, the short shell may also be another barrel section.

[0017] In one embodiment of the present invention, the short shell is obtained by rolling and then longitudinally welding a single hard stainless steel plate.

[0018] In one embodiment of the present invention, the barrel section is obtained by rolling and then longitudinally welding a single hard stainless steel plate.

[0019] In one embodiment of the present invention, the raw material of the curved arc plate is a hard stainless steel plate, other structures except the bottom locking structure are processed in the plate state, and then the arc plate is obtained by sheet metal forming, and finally the bottom locking structure is processed.

[0020] In one embodiment of the present invention, the distance between the connection point between the curved arc plate and the cylinder section and the equatorial plane is 100 mm±5 mm.

[0021] An ultra-thin stainless steel storage tank comprises a short shell, a cylinder section, and two tank bottoms;

[0022] The tank bottom, short shell and cylinder section adopt the connection form of the above-mentioned connection structure for ultra-thin stainless steel tanks;

[0023] The two tank bottoms are located at both ends of the cylinder section, and the tank is connected to the external structure through a short shell.

[0024] Compared with the prior art, the present invention has the following beneficial effects:

[0025] (1) In terms of materials, hard stainless steel plates are selected as raw materials to ensure the performance of the transition ring and avoid the problem of low hot forging performance;

[0026] (2) In terms of design, the connection surface between the transition ring and the barrel section is set at a distance of 100 mm from the equatorial plane, which solves the problem of additional bending moment of the weld at this location; reinforcing strips are introduced into the weak longitudinal seam of the transition ring to solve the problem of performance attenuation caused by the weld;

[0027] (3) In terms of manufacturing, the plate is first machined and then formed into sheet metal, which reduces the amount of processing removal and saves materials; the overall processing process is simple, avoiding the problem of forging ring forming and meeting the low-cost requirements. BRIEF DESCRIPTION OF THE DRAWINGS

[0028] Figure 1 This is the first schematic diagram of the connection structure for ultra-thin stainless steel storage tanks.

[0029] Figure 2 This is the second schematic diagram of the connection structure for the ultra-thin stainless steel storage tank.

[0030] Figure 3 Schematic diagram of the box bottom structure.

[0031] Figure 4 Schematic diagram of the transition ring structure.

[0032] Figure 5 It is a partial schematic diagram of the connection between the transition ring and other components.

[0033] Reference numerals: box bottom 1, cylinder section 3, short shell 2, transition ring 4, circular ring 5, top cover flange 6, curved arc plate 7, reinforcement strip 8. DETAILED DESCRIPTION

[0034] To make the objectives, technical solutions and advantages of the present invention more clear, the embodiments of the present invention will be further described in detail below with reference to the accompanying drawings.

[0035] A connection structure for an ultra-thin stainless steel tank, such as Figure 1 and Figure 2 As shown, it includes a box bottom 1, a short shell 2, and a barrel section 3. The short shell 2 can also be another barrel section.

[0036] like Figure 3 As shown, the box bottom 1 includes a transition ring 4, a circular ring 5 and a top cover flange 6 welded by plate materials. The transition ring 4 and the circular ring 5 are welded together by a circular weld, and the circular ring 5 and the top cover flange 6 are welded together by a circular weld. Figure 3 As shown, the transition ring 4 includes 6 curved arc plates 7 and 6 reinforcing strips 8. Figure 4 As shown. The ring 5 can be made by welding the melon slices or forming them as a whole. The top cover flange 6 can be obtained by machining.

[0037] The short shell 2 can be a barrel section of a common bottom tank or a barrel section of a non-common bottom tank. The short shell 2 is obtained by rolling and bending a single hard stainless steel plate and then longitudinally welding.

[0038] The barrel section 3 may be a tank barrel section structure. The barrel section 3 is obtained by rolling and bending a single hard stainless steel plate and then longitudinally welding it.

[0039] like Figure 4 As shown, the raw material of the curved arc plate 7 is a hard stainless steel plate, and other structures except the bottom locking structure are processed in the plate state, and then the arc plate is obtained by sheet metal forming, and finally the bottom locking structure is processed. Figure 5 As shown, the connection between the curved arc plate 7 and the cylinder section 3 is 100 mm below the equatorial plane of the bottom of the box. This design solves the problem of additional bending moment in the weld caused by the transition from the bottom of the box 1 to the cylinder shell 3, and also avoids the increase in structural weight caused by the introduction of too much material.

[0040] like Figure 4 As shown, a reinforcing strip 8 is provided at the longitudinal seam welding point between the two curved arc plates 7. The reinforcing strip 8 reinforces the weak longitudinal seam and solves the problem of weld performance attenuation in the weakest area caused by the weld.

[0041] like Figure 5 As shown in the partial enlarged figure I, a bottom locking structure is provided in the curved arc plate 7, and the box bottom 1 and the short shell 2 are connected by bottom locking welding. Figure 5 As shown in the partial enlarged view II, the curved arc plate 7 is connected to the barrel section 3 by butt welding, and the connecting portion of the curved arc plate 7 and the barrel section 3 is an equal thickness structure.

[0042] The contents not described in detail in the specification of the present invention belong to the common knowledge of those skilled in the art.

[0043] Although the present invention has been disclosed as above in the form of a preferred embodiment, it is not intended to limit the present invention. Any person skilled in the art may make possible changes and modifications to the technical solution of the present invention by using the methods and technical contents disclosed above without departing from the spirit and scope of the present invention. Therefore, any simple modifications, equivalent changes and modifications made to the above embodiments based on the technical essence of the present invention without departing from the content of the technical solution of the present invention shall fall within the protection scope of the technical solution of the present invention.

Claims

1. A connection structure for an ultra-thin stainless steel tank, characterized in that: It comprises a box bottom (1), a short shell (2), and a cylinder section (3); The box bottom (1) comprises a transition ring (4), a circular ring (5) and a top cover flange (6); the transition ring (4) and the circular ring (5) are connected by a circular weld, and the circular ring (5) and the top cover flange (6) are connected by a circular weld; the transition ring (4) comprises a plurality of curved arc plates (7) and a plurality of reinforcing strips (8); the plurality of curved arc plates (7) are connected by longitudinal seam welding, and the longitudinal seams are reinforced by reinforcing strips (8); A bottom locking structure is provided in the curved arc plate (7), the curved arc plate (7) is connected to the short shell (2) by bottom locking welding, and the curved arc plate (7) is connected to the barrel section (3) by butt welding.

2. The connection structure for an ultra-thin stainless steel tank according to claim 1, characterized in that: The connection portion between the curved arc plate (7) and the barrel section (3) is an equal thickness structure.

3. The connection structure for an ultra-thin stainless steel tank according to claim 1, characterized in that: The circular ring (5) is made by welding melon segments or forming the whole.

4. The connection structure for an ultra-thin stainless steel tank according to claim 1, characterized in that: The top cover flange (6) is manufactured by machining.

5. The connection structure for an ultra-thin stainless steel tank according to claim 1, characterized in that: The short shell (2) can also be another barrel section.

6. The connection structure for an ultra-thin stainless steel tank according to claim 1, characterized in that: The short shell (2) is obtained by rolling and bending a single hard stainless steel plate and then longitudinally welding it.

7. The connection structure for an ultra-thin stainless steel tank according to claim 1, characterized in that: The barrel section (3) is obtained by rolling and then longitudinally welding a single hard stainless steel plate.

8. The connection structure for an ultra-thin stainless steel tank according to claim 1, characterized in that: The raw material of the curved arc plate (7) is a hard stainless steel plate. Other structures except the bottom locking structure are processed in the plate state, and then the arc plate is obtained by sheet metal forming, and finally the bottom locking structure is processed.

9. The connection structure for an ultra-thin stainless steel tank according to claim 1, characterized in that: The distance between the connection point between the curved arc plate (7) and the cylinder section (3) and the equatorial plane is 100 mm±5 mm.

10. An ultra-thin stainless steel storage tank, characterized in that: It comprises a short shell (2), a barrel section (3), and two box bottoms (1); The tank bottom (1), the short shell (2) and the cylinder section (3) are connected in the form of the connection structure for the ultra-thin stainless steel tank as claimed in claim 1; The two tank bottoms (1) are located at the two ends of the cylinder section (3), and the storage tank is connected to the external structure through a short shell (2).

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