Reinforced tunnel pipe with fins

Abstract

The utility model discloses a reinforced tunnel pipe with fins, which belongs to the technical field of spaceflight parts and comprises a corrugated pipe and an external pressure pipeline, the corrugated pipe is fixedly connected with the external pressure pipeline through a connecting flange, and the external pressure pipeline is an integrally formed light pipe. And a plurality of fins are welded on the outer surface of the external pressure pipeline along the length direction of the external pressure pipeline. The tunnel pipe has two characteristics that firstly, the external pressure pipeline with external pressure bearing capacity is an integrally formed light pipe, and the external pressure pipeline is a pipeline without ripples and butt welds and is an integral light pipe, so that the leakage probability is reduced, the reliability is improved, and the service life of the tunnel pipe is prolonged; and secondly, in order to improve the external pressure instability resistance of the tunnel pipe, the external pressure instability resistance can be improved by welding a plurality of fins on the external pressure pipeline, the manufacturing process of the external pressure pipeline is simple, and the manufacturing cost is reduced. Therefore, the tunnel pipe meets the requirement for bearing external pressure, and meanwhile the cost and complexity of the manufacturing process are reduced.

Description

TECHNICAL FIELD

[0001] The utility model relates to aerospace parts technical field, concretely relates to a tunnel pipe with fin reinforced. BACKGROUND

[0002] Rocket tank surface is provided with tank surface connecting flange 8 for connecting with other components, the tunnel pipe is a component in the rocket tank, the tunnel pipe bears the pressure of rocket fuel 6 in the rocket tank 5, and a pipeline passes through the inner cavity of the tunnel pipe, the pipeline is a main fuel pipeline 7, and the tunnel pipe bears external pressure.

[0003] The tunnel pipe structure of prior art is schematically shown as Figure 1 The main components of the tunnel pipe include an aluminum alloy welded corrugated pipe 1' arranged at the end part, and a pipeline 2' with intermittent short waves, wherein the corrugated pipe is mainly used to compensate the deformation of the pipeline caused by low-temperature rocket fuel and reduce the stress of the pipeline, and the short waves are used to increase the external pressure bearing capacity of the pipeline.

[0004] Firstly, the tunnel pipe in the prior art is made of high-strength aluminum alloy to bear external pressure, the weldability of the aluminum alloy is poor, the strength of the weld can only reach 60-70% of that of the base material, the toughness is poor, and the elongation can only reach 15% of that of the base material, so the fatigue life is low and the reliability is not high.

[0005] Secondly, the tunnel pipe in the prior art is formed by a thick-walled seamless aluminum alloy pipe to increase the external pressure bearing capacity of the pipeline, an aluminum alloy plate is punched to form a diaphragm, then the corrugated pipe is welded, and finally the corrugated pipe and the pipeline are assembled to form the tunnel pipe, the seamless aluminum alloy pipe and the diaphragm need to be specially customized, the process is complex, and the cost is high.

[0006] Moreover, the tunnel pipe in the prior art needs to increase the thickness of the pipeline to bear external pressure, which undoubtedly increases the weight of the tunnel pipe, and based on the fact that the corrugated pipe is welded from a diaphragm, the compensation capacity is limited, the fatigue life is low, the welding performance of the aluminum alloy is poor, the reliability of the corrugated pipe is not high, and the corrugated pipe cannot be reused.

[0007] In summary, it is urgent to provide a tunnel pipe that can bear external pressure and has a simpler manufacturing process, which is a problem that needs to be solved in the production process of enterprises. UTILITY MODEL CONTENTS

[0008] Therefore, the utility model aims to provide a tunnel pipe with fin reinforcement to solve the problem that the existing tunnel pipe has a complex manufacturing process while meeting the requirement of bearing external pressure.

[0009] In order to achieve the above object, the utility model discloses a way of setting the fin on the outer pressure pipeline to realize the effect of satisfying the requirement of bearing external pressure while the manufacturing process is simple.

[0010] The utility model discloses a tunnel pipe has two characteristics in the structure, one is that the external pressure pipeline of bearing external pressure capacity is integrally formed light pipe, that is, the external pressure pipeline is the pipeline without corrugation and butt joint weld, is the light pipe of integral, makes the leakage probability reduce, and reliability improves, and compared with the seamless aluminum alloy pipe and diaphragm of external pressure pipeline of prior art needs special customization, and the structure of external pressure pipeline of the utility model discloses can directly adopt the integrally formed light pipe, therefore the cost of external pressure pipeline of the utility model discloses is lower, and the manufacturing cost of the whole tunnel pipe of the utility model discloses is reduced.

[0011] Based on the above, the thickness of the fin is 2mm-6mm, and the height of the fin is 30mm-60mm.

[0012] Based on the above, the fins are uniformly distributed on the outer surface of the external pressure pipeline along the length direction of the external pressure pipeline.

[0013] Based on the above, the spacing between the adjacent two fins is 200mm-500mm.

[0014] Based on the above, the fin is a stainless steel fin.

[0015] In the utility model, the fin height, fin thickness, fin spacing and fin material all affect the ability of the external pressure pipeline to bear external pressure, therefore, in order to effectively meet the requirement of bearing external pressure, the thickness and height of the fin are set accordingly, the distance between the adjacent fins is also required, and the stainless steel fin with strong weldability and high elongation is used as the fin of the utility model to meet the requirement of the diameter of the tunnel pipe and the size of the bearing external pressure.

[0016] Based on the above, the corrugated pipe is a thin-walled plate one-time forming stainless steel corrugated pipe.

[0017] Compared with the aluminum alloy plate in the prior art, the stainless steel plate has good welding performance, good toughness, good weldability and high elongation, and the weight of the tunnel pipe is reduced by using the thin-wall plate, the material is integrally formed, the reliability is higher, and the overall fatigue life is also improved.

[0018] Based on the above, the integrally formed light pipe of the outer pressure pipeline is a thin-wall stainless steel pipe.

[0019] In the utility model, on the one hand, the weight of the tunnel pipe is reduced by using the thin-wall stainless steel pipe, and on the other hand, the stainless steel has good welding performance, good toughness, good weldability and high elongation, so that the manufacturing process of the tunnel pipe is simplified, the manufacturing cost is greatly reduced, the weight of the tunnel pipe can be effectively reduced under the condition of ensuring the performance requirements, the reliability is increased, the manufacturing cost is reduced, the rocket take-off capacity is increased, and the tunnel pipe can be repeatedly used, which provides a reliable part for future return type rockets.

[0020] Based on the above, the fin is a circular fin.

[0021] The ability of the pipeline to withstand external pressure depends on whether the deformation of the pipeline under external pressure will cause the pipeline to lose stability, since the pipeline is thin-walled and long, the material performance, structure size, shape and size are different, the instability of the pipeline usually starts from a point to cause large deformation of the pipeline (the cross section changes from a circle to an irregular shape), therefore the thin-wall pipeline has weak ability to withstand external pressure, and a reinforcing device is needed when the external pressure is large, in the utility model, the radial stiffness of the pipeline can be increased by setting the fins to prevent large deformation of the pipeline, and the anti-external pressure instability ability of the pipeline can be increased, wherein the types of fins, such as spiral fins, circular fins, sawtooth fins and fan-shaped fins, can all achieve the effect of increasing the anti-external pressure instability ability of the pipeline. However, based on the space product, under the condition of ensuring strength and stiffness, it is hoped that the product weight can be reduced to the maximum extent, the material and wall thickness of the tunnel pipe, the material and structure of the fin need to be quantitatively determined by using finite element analysis method, and factors such as manufacturing process and manufacturing cost also need to be considered, therefore, the circular fin is adopted as the optimal scheme in the utility model.

[0022] The above description is only a summary of the technical scheme of the utility model, in order to more clearly understand the technical means of the utility model, the content of the specification can be implemented, and in order to make the above and other purposes, characteristics and advantages of the utility model more obvious and easy to understand, the following preferred embodiments are described in detail, and the accompanying drawings are described as follows. BRIEF DESCRIPTION OF DRAWINGS

[0023] Figure 1 The tunnel pipe structure schematic diagram used in the prior art.

[0024] Figure 2 This is a schematic diagram of the tunnel pipe structure of this utility model.

[0025] In the diagram: 1'-Aluminum alloy welded corrugated pipe; 1-One-piece molded stainless steel corrugated pipe; 2'-Pipe with intermittent low corrugations; 2-Thin-walled stainless steel bare pipe; 3-Pipe connection flange; 4'-Low corrugations; 4-Fins; 5-Rocket tank; 6-Rocket fuel; 7-Main fuel pipeline; 8-Tank surface connection flange. Detailed Implementation

[0026] The technical solution of this utility model will be clearly and completely described below with reference to specific implementation schemes. However, those skilled in the art should understand that the implementation schemes described below are only for illustrating this utility model and should not be regarded as limiting the scope of this utility model. Based on the implementation schemes in this utility model, all other implementation schemes obtained by those skilled in the art without creative effort are within the protection scope of this utility model.

[0027] Example of finned reinforced tunnel pipe

[0028] The finned reinforced tunnel pipe of this embodiment achieves the effect of meeting the external pressure requirements while simplifying the manufacturing process by welding multiple fins onto the external pressure pipe of the integrally formed smooth tube.

[0029] like Figure 2 As shown, the tunnel pipe in this embodiment includes a corrugated pipe (i.e., a one-piece molded stainless steel corrugated pipe 1) and an external pressure pipe (a thin-walled stainless steel plain pipe 2). The corrugated pipe and the external pressure pipe are fixedly connected by a pipe connection flange 3. The external pressure pipe is a one-piece molded plain pipe, and several fins 4 are welded on the outer surface of the external pressure pipe along the length of the external pressure pipe.

[0030] Based on this embodiment, the external pressure pipeline is designed as a one-piece molded smooth pipe without corrugations or butt welds, i.e., a single, monolithic smooth pipe. This reduces the probability of leakage and improves reliability. Furthermore, the structure of this one-piece molded smooth pipe external pressure pipeline can directly utilize existing one-piece molded smooth pipes, thus reducing the cost of the external pressure pipeline in this embodiment, and consequently reducing the overall manufacturing cost of the tunnel pipe. In addition, this embodiment improves the tunnel pipe's resistance to external pressure instability by welding several fins onto the external pressure pipeline. This improvement method is simple to manufacture and reduces manufacturing costs. Therefore, the tunnel pipe of this embodiment meets the requirements for withstanding external pressure while reducing the cost and complexity of the manufacturing process.

[0031] To facilitate assembly within the confined space of the storage tank, tunnel pipe connections are achieved via flange connections, such as... Figure 2 As shown, the one-piece molded stainless steel corrugated pipe 1 can compensate for installation deviations and displacement due to pipe temperature changes.Figure 2 The pipe connecting flange 3 at the left end of the one-off formed stainless steel bellows 1 is used for connecting the one-off formed stainless steel bellows 1 with a storage tank, and the connecting flange at the other end is used for connecting with the thin-walled stainless steel light pipe 2. The pipe connecting flange 3 at the right end of the thin-walled stainless steel light pipe 2 is used for connecting the thin-walled stainless steel light pipe 2 with the storage tank, thus forming a complete channel for isolating the medium in the storage tank.

[0032] The thickness, height and spacing of the fins in the embodiment can be adjusted according to the working conditions, so that the external pressure can be effectively borne. In order to effectively meet the need of bearing external pressure, the thickness and height of the fins themselves, the distance between adjacent fins and the material of the fins in the embodiment can be set as follows:

[0033] The fins are uniformly distributed on the outer surface of the external pressure pipeline along the length direction of the external pressure pipeline. The fin material is 0cr19ni10 stainless steel. According to the diameter of the tunnel pipe and the need to bear external pressure, the fin thickness is 2mm-6mm, the fin height is 30mm-60mm, and the fin spacing is 200mm-500mm.

[0034] The external pressure pipeline of the embodiment also uses 0cr19ni10 stainless steel. Therefore, the tunnel pipe of the embodiment uses the existing thin-walled stainless steel pipe on the market, and then welds fins on the stainless steel pipe according to the need of the working conditions. The process is simple and the cost is very low.

[0035] It is considered that the ability of the pipeline to bear external pressure depends on whether the deformation of the pipeline under external pressure will lead to the instability of the pipeline. Since the pipeline is thin-walled and long in structure, the material performance, structural size, shape and size are different, and the instability of the pipeline usually starts from a point where large deformation leads to the instability of the pipeline (the cross section changes from a circle to an irregular shape). Therefore, the thin-walled pipeline has weak ability to bear external pressure, and a reinforcing device is needed when the external pressure is large. Regardless of the spiral fin, the circular fin, the sawtooth fin or the fan-shaped fin, the radial stiffness of the pipeline can be increased to prevent large deformation of the pipeline, and the anti-external pressure instability ability of the pipeline can be increased. Therefore, the fins of the embodiment can use any one of the spiral fin, the circular fin, the sawtooth fin and the fan-shaped fin to meet the needs.

[0036] It is considered that in the case of ensuring strength and stiffness, the weight of the aerospace product is expected to be reduced to the maximum extent. The material and wall thickness of the tunnel pipe, the material and structure of the fin need to be quantitatively determined by using finite element analysis method, and factors such as manufacturing process and manufacturing cost also need to be considered. At present, the circular fin is the optimal scheme. Therefore, as other embodiments, the circular fin can be used as the fin welded on the outer surface of the external pressure pipeline.

[0037] The bellows of the embodiment adopts a stainless steel bellows formed by a thin-wall sheet in one step, and also adopts a 0cr19ni10 thin-wall sheet, and is integrally formed in one step, compared with the aluminum alloy sheet, the stainless steel has good welding performance, good ductility, good weldability, high elongation, and the weight of the tunnel pipe is reduced by using the thin-wall sheet, and based on the integrally formed material, the reliability is higher, and the overall fatigue life is also improved accordingly. Therefore, the bellows at the end of the tunnel pipe of the embodiment adopts a stainless steel thin-wall sheet one-step forming process, and has higher reliability and higher fatigue life.

[0038] Based on the tunnel pipe of the embodiment, the 0cr19ni10 stainless steel is selected as the material, the stainless steel has good welding performance, the weld strength can reach more than 95% of the base material, has good toughness, the elongation can reach more than 45% of the base material, has good welding performance and elongation, has very high low-temperature strength, and on the structure, the fins are uniformly distributed on the external pressure pipeline, and the thickness, height and interval of the fins are adjusted according to the working condition, which can effectively meet the need of bearing external pressure, the bellows at the end of the tunnel pipe adopts a stainless steel thin-wall sheet one-step forming process, and has higher reliability and higher fatigue life.

[0039] In summary, the key point of the embodiment is a tunnel pipe with a special design structure, which adopts stainless steel material, and a plurality of fins are welded on the overall thin-wall pipeline to meet the need of the tunnel pipe to resist external pressure, compared with the ordinary tunnel pipe, has lower weight, simpler manufacturing process, better safety and economy, and can be reused, the bellows at the end adopts a stainless steel thin-wall sheet one-step forming process, has higher reliability and higher fatigue life. Due to the material characteristics and structural characteristics of the tunnel pipe of the embodiment, the tunnel pipe can effectively reduce the weight, increase the reliability, reduce the manufacturing cost and increase the launch capacity of the rocket under the condition of ensuring the performance requirements, and the tunnel pipe can also be reused, which provides a reliable part for the future return type rocket.

[0040] Although the utility model has been described in detail above with general description and specific embodiments, some modifications or improvements can be made on the basis of the utility model, which is obvious to those skilled in the art. Therefore, these modifications or improvements made on the basis of not deviating from the spirit of the utility model, all belong to the scope of protection required by the utility model.

Claims

1. A fin-stiffened tunnel tube comprising a corrugated pipe, characterized in that, The outer pressure pipeline is integrally formed and is a light pipe, and a plurality of fins are welded on the outer surface of the outer pressure pipeline along the length direction of the outer pressure pipeline.

2. The fin-stiffened tunnel tube of claim 1, wherein, The thickness of the fins is 2-6 mm, and the height of the fins is 30-60 mm.

3. The fin-stiffened tunnel tube of claim 1, wherein, The fins are uniformly distributed on the outer surface of the outer pressure pipeline along the length direction of the outer pressure pipeline.

4. The fin-stiffened tunnel tube according to claim 1 or 3, characterized in that, The interval between two adjacent fins is 200-500 mm.

5. The fin-stiffened tunnel tube of claim 1, wherein, The fins are stainless steel fins.

6. The fin-stiffened tunnel tube of claim 1, wherein, The corrugated pipe is a stainless steel corrugated pipe formed by one-time forming of a thin-walled plate.

7. The fin-stiffened tunnel tube of claim 1, wherein, The integrally formed light pipe of the outer pressure pipeline is a thin-walled stainless steel pipe.

8. The fin-stiffened tunnel tube of claim 1, wherein, The fins are circular fins.

Images