Corrugated assembly for pressure regulating valve of environmental control system

Abstract

The invention belongs to the field of pressure reducers of environmental control systems, and relates to a corrugated assembly for a pressure regulating valve of an environmental control system. The corrugated assembly comprises a top cover, an upper cover, a spring, a reducing corrugated pipe, a lower cover and a guide sleeve; the lower cover comprises a lower cover body and a cylindrical boss arranged in the center of the circular cover body, the cylindrical boss is sleeved with a guide sleeve, and the cylindrical boss is fixedly connected with the guide sleeve; the upper cover comprises an upper cover body and a cylinder arranged in the center of the lower end face of the lower cover body. The guide sleeve is inserted into the cylinder, the spring is sleeved between the upper cover and the lower cover, the upper cover, the guide sleeve, the spring and the lower cover form a piston-like structure, the piston-like structure is arranged in the variable-diameter corrugated pipe, the lower end of the variable-diameter corrugated pipe is arranged on the lower cover body, the upper end of the variable-diameter corrugated pipe is arranged on the lower end face of the top cover, and a stepped hole is formed in the top cover and is large in bottom and small in top. The step surface abuts against the upper cover body.

Description

TECHNICAL FIELD

[0001] The present application belongs to the field of pressure reducer of environmental control system, and relates to a corrugated assembly for pressure regulating valve of environmental control system. BACKGROUND

[0002] The pressure reducer of environmental control system senses the change of system pressure through the regulating corrugated pipe, generates corresponding displacement, and achieves the function of regulating the opening of valve, thereby reducing pressure and maintaining the pressure in the cavity.

[0003] The original corrugated pipe assembly of copper alloy has the problems of air leakage at the welding surface, cracking of the wave crest and wave trough at both ends of the corrugated pipe, and poor reliability. According to the failure analysis, the failure mode of the original structure of the regulating corrugated pipe assembly is fatigue corrosion, the structure has weak fatigue resistance, the environment has strong corrosion, and the combination thereof leads to cracking of the corrugated pipe or air leakage of the welding seam. SUMMARY

[0004] The present application aims to provide a corrugated assembly for pressure regulating valve of environmental control system, which has the advantages of improving fatigue strength, corrosion resistance, radial load capacity and stability, reducing the risk of air leakage and cracking of the corrugated pipe, increasing axial guidance and limiting, and improving product reliability.

[0005] TECHNICAL SCHEME The present application provides a corrugated assembly for pressure regulating valve of environmental control system, which comprises a top cover, an upper cover, a spring, a variable-diameter corrugated pipe, a lower cover and a guide sleeve. The lower cover comprises a lower cover body and a cylindrical boss arranged at the center of the circular cover body, the cylindrical boss is sleeved with the guide sleeve, and the cylindrical boss and the guide sleeve are fixedly connected; the upper cover comprises an upper cover body and a cylindrical barrel arranged at the center of the lower end surface of the lower cover body; the guide sleeve is inserted into the cylindrical barrel, and the spring is sleeved between the upper cover and the lower cover to form a piston-like structure, and the piston-like structure is arranged in the variable-diameter corrugated pipe; the lower end of the variable-diameter corrugated pipe is installed on the lower cover body, and the upper end is installed on the lower end surface of the top cover; the top cover is provided with a stepped hole, the stepped hole is large at the lower end and small at the upper end, and the stepped surface abuts against the upper cover body.

[0006] Further, the upper end surface of the guide sleeve is flush with the upper end surface of the cylindrical boss, and the boss end surface is flush and fixedly bonded.

[0007] Further, the top cover and the lower cover body are connected with the variable-diameter corrugated pipe by vacuum electron beam welding; the straight pipe end of the variable-diameter corrugated pipe is connected with the top cover, and the straight pipe end is connected with the lower cover body.

[0008] Further, the combination of the lower cover and the guide sleeve is slidably connected with the inner groove of the upper cover cylinder and moves along the axial direction, forms an axial limiting structure with the upper cover, and can also limit the radial deflection.

[0009] Further, the variable-diameter corrugated pipe has a double-layer variable-diameter structure with small ends and a large middle portion.

[0010] Furthermore, the top cover, upper cover, spring, variable diameter bellows, and lower cover are all made of stainless steel.

[0011] Furthermore, the guide sleeve is made of polytetrafluoroethylene.

[0012] Furthermore, the top cover and the bottom cover are connected to both ends of the variable diameter bellows by vacuum electron beam welding.

[0013] Beneficial effects: This invention meets the pressure regulation performance requirements of environmental control systems, solves the problems of easy air leakage at the welded surface of the lower cover of the original bellows assembly and easy fatigue corrosion cracking of the bellows, improves the materials, structure and process, and enhances the product's fatigue strength, corrosion resistance, stability, reliability, economy and environmental protection. Attached Figure Description

[0014] Figure 1 This is a schematic diagram of the pressure regulating bellows assembly; Figure 2 is a schematic diagram comparing the stress of the old and new bellows; Figure 3 This is a schematic diagram of the working principle of the pressure regulating bellows assembly; Among them, 1'-air inlet nozzle; 2'-sealing ring; 3'-base; 4'-sealing ring; 5'-sealing ring; 6'-outer cylinder; 7-top rod; 8-inner cylinder assembly; 9-corrugated assembly; 10-locking ring; 11-sealing ring; 12-adjusting screw; 13-sealing ring; 14-top cover; 15-locking screw; 16-sealing ring; 17-sealing ring; 18-filter element; 19-valve; 20-spring; 21-slotted countersunk screw; 22-sealing ring. Detailed Implementation

[0015] This embodiment provides a bellows assembly for a pressure regulating valve in an environmental control system. See [link to previous document]. Figure 1 The corrugated pipe assembly includes a top cover 1, an upper cover 2, a spring 3, a corrugated pipe 4, a lower cover 5, and a guide sleeve 6. The guide sleeve 6 is installed on the cylindrical boss of the lower cover 5 and flush with the end face, and is bonded and fixed. The spring 3 is installed on the lower end face of the upper cover 2 and placed in the inner groove of the top cover 1. The assembly of the lower cover 5 and the guide sleeve 6 is inserted into the cylindrical inner groove of the upper cover 2 for guiding and engagement, and then removed and installed into the corrugated pipe. The top cover 1 and the lower cover 5 are connected to both ends of the variable diameter corrugated pipe 5 by vacuum electron beam welding.

[0016] The outer side of the large cylindrical boss on the top cover 1 is provided with fine threads for installing and fixing the pressure regulating bellows assembly and for static sealing. Above the external thread, there is a flat end face for installing a locking ring and a drainage slope. Below, there is a 45° welded boss structure, with the thickness at the weld position approximately the same as the bellows wall thickness. There is a circular groove inside.

[0017] The small cylindrical boss on the top cover 1 has a threaded hole inside for installing an adjusting screw. A sealing groove is located at the upper part of the cylindrical boss for installing a sealing ring. The lower end of the sealing groove is milled for easy installation and positioning, as well as weight reduction. A through hole is opened at the lower internal end, allowing the screw to contact the top cover and simultaneously connect to the internal venting of the product.

[0018] The upper part of the top cover 2 is a disc that slides into the inner groove of the top cover 1 without friction. A spring 3 is installed on the back of the disc. After installation, the spring is in a compressed state, pressing the disc against the top cover. There is a trapezoidal groove with a 120° opening in the middle of the disc, which communicates with a small hole in the lower cylinder for venting. The end face of the trapezoidal groove is pressed by an adjusting screw, and the pressure can be adjusted by compressing the spring through the top cover 2.

[0019] The lower part of the upper cover 2 is a long cylinder with an outer diameter that matches the inner diameter of the spring 3, which facilitates installation, guidance, and limiting. The inner diameter has a frictionless fit with the outer diameter of the guide sleeve 6, providing axial guidance, limiting, and suppressing radial runout, thereby improving load-bearing capacity.

[0020] Spring 3 is installed between the upper cover 2 and the lower cover 5. After installation, it is in a compressed state and provides the main preload force to the pressure regulating bellows assembly.

[0021] Furthermore, the spring material is stainless steel wire with a wire diameter of Φ1.8mm, an inner diameter of Φ9.2mm, an effective number of coils of 4, a total number of coils of 6, and the end face is ground flat for easy installation.

[0022] The variable diameter bellows 4 has U-shaped corrugations and is installed between the top cover 1 and the bottom cover 5 by welding. It provides elasticity, isolates internal and external environmental pressure, and can output displacement by sensing changes in pressure difference.

[0023] Furthermore, the reducing corrugated pipe 4 is made of double-layer stainless steel (06Cr19NI10). It has 6 U-shaped corrugations with a thickness of 0.10mm±0.01mm. The inner diameter of the flat end of the corrugated pipe is Φ18.9±0.5mm, and the inner diameter from the second trough to the end is Φ17.7±0.5mm. The outer diameter of the first peak of both the flat end and the straight end is Φ29.4±0.5mm, and the outer diameter of the middle peak is Φ32.6±0.5mm.

[0024] Furthermore, compared to the original corrugated pipe structure, the variable diameter corrugated pipe 4 has smaller peak and valley deformation at its fixed end, resulting in less stress, reduced risk of rupture, and improved fatigue life. The outer circle of the large cylindrical boss of the lower cover 5 is fitted to the straight pipe opening of the corrugated pipe 4. An annular truncated cone with a wall thickness approximately the same as that of the straight pipe opening of the corrugated pipe 4 is provided on the edge of the outer circle for welding. A clearance step is provided at the bottom of the weld to avoid direct contact between the weld and the mounting surface, which could cause collision, wear, and the risk of air leakage.

[0025] The outer circle of the small cylindrical boss of the lower cover 5 matches the inner diameter of the guide sleeve 6. After being bonded and fixed to the guide sleeve, it extends into the cylinder of the upper cover 2 for guiding engagement.

[0026] Furthermore, the lower cover 5 has a deep hole inside, and the hole depth exceeds the end face of the cylinder after the upper cover 2 and the lower cover 5 are fitted together. After being installed with the external top rod, it has a better ability to suppress radial runout.

[0027] Furthermore, the top cover 1, upper cover 2, spring 3, bellows 4, and lower cover 5 are all made of stainless steel, which offers better weldability and compatibility compared to the original copper alloy structure.

[0028] Furthermore, the guide sleeve 6 is made of polytetrafluoroethylene, which can serve as a buffer, lubricant, reduce friction, and guide.

[0029] Furthermore, vacuum electron beam welding is used instead of the original tin brazing. This results in a smaller heat-affected zone, higher energy density, higher welding quality, and greater weld strength. Welding in a vacuum environment produces a purer weld compared to tin brazing, eliminating the risk of oxidation and impurity contamination.

[0030] like Figure 2a.1 , 2a.2 As shown in 2b.1 and 2b.2, comparing the stress of the original corrugated pipe structure with the stress of the variable diameter corrugated pipe proposed in this embodiment, it is obvious that the technical solution of this application is superior and has a better stress effect.

[0031] This invention provides a bellows assembly 9 for a pressure regulating valve in an environmental control system, installed inside a pressure reducer, such as... Figure 3 As shown, the pressure reducer includes: an air inlet 1', a sealing ring 2', a base 3', a sealing ring 4', a sealing ring 5', an outer cylinder 6', a push rod 7, an inner cylinder assembly 8, a locking ring 10, a first sealing ring 11, an adjusting screw 12, a second sealing ring 13, a top cover 14, a locking screw 15, a third sealing ring 16, a fourth sealing ring 17, a filter element 18, a valve 19, a spring 20, a slotted countersunk screw 21, and a fifth sealing ring 22.

[0032] When the environmental control system pressure increases, the pre-pressure of the pressure regulating bellows assembly opens the valve through the action of the push rod installed in the inner groove of the lower cover. Gas enters the cylinder (the cavity where the bellows is located) and acts on the bellows assembly. As the pressure inside the cylinder further increases, the bellows assembly is gradually compressed. Through the action of the spring valve and the push rod, the opening height of valve 19 decreases until it closes. At this time, the environmental control system pressure cannot directly enter the cylinder, maintaining the pressure inside the cylinder. The gas pressure inside the cylinder slowly decreases after passing through the filter element until the elastic force on the bellows assembly is greater than the pressure of the surrounding gas. Then, the bellows assembly elongates, the balancing valve mechanism reopens, and gas re-enters the cylinder, maintaining the pressure inside the cavity.Figure 3 As shown.

[0033] The pressure regulating bellows assembly achieves the function of adjusting the valve opening, thereby reducing pressure and maintaining the pressure inside the cavity.

[0034] Other embodiments of this disclosure will readily occur to those skilled in the art upon consideration of the specification and practice of the disclosure herein. This application is intended to cover any variations, uses, or adaptations of this disclosure that follow the general principles of this disclosure and include common knowledge or customary techniques in the art not disclosed herein. The specification and examples are to be considered exemplary only, and the true scope and spirit of this disclosure are indicated by the following claims.

[0035] It should be understood that this disclosure is not limited to the precise structures described above and shown in the accompanying drawings, and various modifications and changes can be made without departing from its scope. The scope of this disclosure is limited only by the appended claims.

Claims

1. A corrugated assembly for a pressure regulating valve in an environmental control system, characterized in that, include: Top cover (1), upper cover (2), spring (3), variable diameter bellows (4), lower cover (5), guide sleeve (6); The lower cover (5) includes a lower cover body and a cylindrical boss located at the center of the circular cover body. A guide sleeve (6) is fitted on the cylindrical boss, and the cylindrical boss and the guide sleeve are fixedly connected. The upper cover (2) includes an upper cover body and a cylindrical tube located at the center of the lower end face of the lower cover body. The guide sleeve is inserted into the cylindrical tube, and the spring (3) is fitted between the upper and lower covers. The upper cover, guide sleeve, spring and lower cover form a piston-like structure. The piston-like structure is installed in the variable diameter bellows (4). The lower end of the variable diameter bellows (4) is installed on the lower cover body, and the upper end is installed on the lower end face of the top cover (1). The top cover is provided with a stepped hole. The stepped hole is larger at the bottom and smaller at the top. The stepped surface abuts against the upper cover body.

2. The assembly according to claim 1, characterized in that, The upper end face of the guide sleeve is flush with the upper end face of the cylindrical boss, and the boss end face is flush and bonded together.

3. The assembly according to claim 1, characterized in that, The top cover (1) and the lower cover are connected to the variable diameter bellows (4) by vacuum electron beam welding; the flat end of the bellows (5) is connected to the top cover (1), and the straight end is connected to the lower cover.

4. The assembly according to claim 1, characterized in that, The combination of the lower cover (5) and the guide sleeve (6) slides in the inner groove of the upper cover (2) cylinder, moves along the axial direction, and forms an axially limited structure with the upper cover (2), which can also limit radial deflection.

5. The assembly according to claim 1, characterized in that, The variable diameter bellows (4) is a double-layer variable diameter structure with small ends and large middle.

6. The assembly according to claim 1, characterized in that, The top cover (1), upper cover (2), spring (3), variable diameter bellows (4), and lower cover (5) are all made of stainless steel.

7. The assembly according to claim 1, characterized in that, The guide sleeve (6) is made of polytetrafluoroethylene.

8. The assembly according to claim 1, characterized in that, The top cover (1) and the bottom cover (5) are connected to both ends of the variable diameter bellows (4) by vacuum electron beam welding.

Images