Pipeline supporting structure for vacuum delay line system of long-baseline optical interferometer

Abstract

The invention discloses a pipeline support structure for a vacuum delay line system of a long baseline optical interferometer, which comprises a vacuum pipeline, a cat eye type retroreflector, a linear motor module and an inner support assembly, and is characterized in that the inner support assembly comprises a plane adapter plate and a fillet lower collet, the plane adapter plate is connected with a guide rail system, and the guide rail system is connected with the linear motor module; the lower side of the fillet lower bottom support is of an arc-shaped structure and is fixedly attached to the inner wall of the vacuum pipeline. The supporting structure further comprises an outer supporting assembly, and the outer supporting assembly comprises two outer supporting fixing pieces symmetrically installed outside the vacuum pipeline. The supporting structure has good installation planeness, structural stability and adjustment flexibility, can effectively solve the problems that in the prior art, a supporting structure in a round pipe is insufficient in stability and cannot be adjusted, and the installation precision is difficult to guarantee, and is particularly suitable for a precise astronomical optical instrument installation platform which is strict in high planeness and vacuum environment requirements.

Description

Technical Field

[0001] The present invention belongs to the field of optical interference in astronomical telescope technology, and relates to a key support structure for a vacuum delay line system pipeline of an optical interferometer in astronomical telescope technology, which is used to form support inside and outside a vacuum pipeline. Background Art

[0002] With the increasing precision requirements of modern astronomical observations, interferometry techniques are increasingly being used in ground-based optical astronomical observations. In particular, the development of long-baseline optical interferometer technology has enabled astronomers to overcome the limitations of a single telescope's aperture and achieve observation capabilities far exceeding the angular resolution of traditional telescopes. By synthesizing and interfering light beams collected by multiple spatially separated telescopes, long-baseline interferometers can achieve high-precision detection of targets such as stellar surface structures, binary star orbits, and Earth-like planets. During interferometric observations, the time at which light waves from the same target object are received by different telescopes varies slightly, resulting in optical path differences. To achieve coherent superposition of these light waves along different paths in the interferometer, a delay line system is required to compensate for this path difference. The delay line system is a key subsystem in the interferometer, and its performance directly impacts the quality of the interference fringes and the measurement accuracy.

[0003] However, factors such as refractive index fluctuations, temperature changes, and humidity disturbances in the air can affect light propagation, leading to optical path errors and reducing the stability and observation accuracy of the interferometer. Especially in long-baseline structures, the optical path compensation distance can reach tens or even hundreds of meters, making it more sensitive to environmental disturbances. Therefore, to ensure high-precision and stability of optical path adjustment, more and more interferometers are using delay line systems in a vacuum environment. Vacuum delay line systems achieve dynamic adjustment of the optical path length by precisely moving a reflector in a vacuum tube. This not only effectively eliminates the uncertainty caused by air disturbances, but also significantly reduces the system's thermal noise and scattering interference, thereby improving the signal-to-noise ratio of interferometric observations. As the interferometer baseline length continues to grow, higher requirements are placed on the accuracy, stability, control precision, and environmental adaptability of the delay line system. Existing delay line systems mainly use structures such as mechanical slides, trolley optical paths, and vacuum guide rails. They generally have problems such as large size, complex structure, limited motion accuracy, and difficult maintenance. They are also not easily adapted to the needs of different interferometer systems. Therefore, there is an urgent need for a high-performance vacuum delay line system with a more compact structure, more flexible adjustment, stronger environmental adaptability and lower maintenance cost to meet the development needs of future large-scale long-baseline optical interferometers.

[0004] Line contact exists in the design of key support components for the vacuum delay line system of an optical interferometer. Line contact is an idealized model used in mechanical engineering to describe the contact state between two objects. It means that when two rigid bodies are in contact, the idealized contact area is a line, rather than a point or a surface. Line contact has characteristics such as a narrow and long contact area in a strip shape, high contact stress concentration, and the Hertzian contact effect caused in elastic bodies. The contact between the vacuum cylindrical pipe and the optical plane forms an idealized line contact relationship. This structure is indeed common in telescope design, especially in optical support or interface structures in a vacuum environment, but its stability and contact stiffness are indeed a design difficulty. Summary of the Invention

[0005] In order to solve the problems of complex pipeline support structure, difficult adjustment, and high installation flatness requirements of the vacuum delay line system in long-baseline optical interferometers, the present invention proposes a vacuum pipeline support structure with both fixity and adjustability. The structure is suitable for the stable installation of high-precision optical systems in a vacuum environment, and is particularly suitable for supporting the linear motion system of the "cat's eye" type retroreflector in long-baseline optical interferometers.

[0006] To achieve the above object, the present invention provides the following technical solutions:

[0007] A pipeline support structure for a long-baseline optical interferometer vacuum delay line system comprises: a vacuum pipeline mounted on an optical plane; a "cat's eye" type retroreflector and its linear motor module located inside the vacuum pipeline; an internal support assembly disposed inside the vacuum pipeline, the internal support assembly comprising a planar adapter plate and a rounded lower base, the planar adapter plate being connected to the guide rail system of the linear motor module and being fixed to the rounded lower base on both sides thereof via a fine-tuning assembly, the lower side of the rounded lower base being an arc-shaped structure that fits and fixes to the inner wall of the vacuum pipeline. The present invention adopts a combined structural design of a planar adapter plate and a rounded lower base, significantly improving the support stiffness and assembly consistency of the overall structure by installing the guide rail system on a plane with adjustable characteristics and utilizing the natural fit of the arc structure with the inner wall of the vacuum pipeline. The support structure has a high-flatness installation capability, can meet the operating requirements of the linear motor module, and has good structural stability and adaptability to vacuum environments. Among them, the flat adapter plate has good processing flexibility and installation freedom. Its hole position can be flexibly adjusted according to the guide rail installation requirements and the lower base structure, and can be used as a welding positioning template during the installation process to ensure the accuracy of the relative position between the bases, and fine-tuning operations can be performed before and after welding; the rounded lower base adopts an arc surface to fit the inner wall of the vacuum pipeline, which not only enhances the fitting stability of the structure, but also realizes precise control of the installation height through the circular geometric characteristics.

[0008] Furthermore, the upper side of the rounded lower base is a stepped structure, and the planar adapter plate is connected to the rounded lower base on both sides through the stepped structure.

[0009] Furthermore, the fine-tuning assembly includes a fixing screw and an adjusting screw. The fixing screw connects and fixes the plane adapter plate and the rounded lower base into one through threaded engagement. The adjusting screw is threadedly engaged with the plane adapter plate, and the adjusting screw abuts against the height limit hole on the rounded lower base.

[0010] Furthermore, the rounded lower base is an integrated structure or a multi-section spliced structure. The present invention can be designed as an integrated or multi-section spliced structure according to actual engineering requirements, has good manufacturing compatibility and assembly adaptability, and significantly improves the flexibility of engineering implementation.

[0011] Furthermore, the installation method of the internal support assembly includes the following steps: first, connecting the flat adapter plate to the rounded lower base to form pre-assembled assembly 1; then, fixing pre-assembled assembly 1 to the inner wall of the vacuum pipe through the arc-shaped structure on the underside of the rounded lower base; then, removing the flat adapter plate and connecting it to the guide rail system to form pre-assembled assembly 2; finally, adjusting the posture of pre-assembled assembly 2 through the fine-tuning assembly. Its installation method is scientific and reasonable, adopting the process of "fixing first, then welding, and then assembling the guide rail." This not only ensures the control of structural parallelism during the welding process, but also allows for final fine-tuning of the positioning later through support adjustment screws located within the structure, thereby ensuring the long-term stable operation and high-precision performance requirements of the system in a vacuum environment.

[0012] Furthermore, by varying the width or thickness of the planar adapter plate, the installation height of the pre-assembled component relative to the vacuum line can be altered, thereby adjusting the height of the optical axis of the optical path. The internal support assembly features multi-level modularization, allowing for the replacement or expansion of modular units to accommodate varying optical path center heights and telescope aperture configurations, thereby enhancing the system's versatility and engineering adaptability.

[0013] Furthermore, the entire structure of the pre-assembled component 1 is first fixed to the inner wall of the vacuum pipeline by spot welding, and then the parallelism between the pre-assembled component 1 and the optical plane is maintained by using a plane adapter plate and an external reference fixture during the welding process.

[0014] Furthermore, it also includes an external support assembly, which includes two external support fixings symmetrically installed outside the vacuum pipeline, and the external support fixings include a bent plate portion and a straight plate portion. The bent plate portion fits the outer wall of the vacuum pipeline, and the upper ends of the two bent plate portions are fixedly connected by clearance fit. The bent plate portion transitions to the straight plate portion along the vertical tangent, and the lower end of the straight plate portion is fixed to the optical plane.

[0015] Furthermore, a fixing bolt is passed through the connection between the upper ends of the two bent plate parts, and the fixing bolt cooperates with the adjusting nut to adjust the size of the gap between the upper ends of the two bent plate parts.

[0016] Furthermore, the straight plate portion and the optical plane are connected by means of external support screws of the pipeline, and the gap between the external support fixing member and the optical plane is adjusted by means of the external support screws of the pipeline.

[0017] Compared with the prior art, the present invention has the following beneficial effects:

[0018] While meeting the high-precision guide rail operation requirements of the optical interferometer, the present invention takes into account structural strength, vacuum adaptability, installation convenience and reusability, and has good installation flatness, structural stability and adjustment flexibility. It has the advantages of clear principles, reasonable structure, easy processing and implementation, high assembly precision, strong adjustability, and good long-term operation stability. It can effectively solve the problems of insufficient stability, non-adjustability and difficulty in ensuring installation precision of the support structure in the circular tube in the prior art, and is particularly suitable for the installation platform of precision astronomical optical instruments with strict requirements on high flatness and vacuum environment. BRIEF DESCRIPTION OF THE DRAWINGS

[0019] Figure 1 It is a schematic diagram of the installation of the support structure of the present invention in a vacuum pipe.

[0020] Figure 2 This is an exploded view of the main components of the support structure.

[0021] Figure 3 It is an assembly diagram of the connection between the upper support plate and the lower support frame.

[0022] Figure 4 This is a diagram showing the fitting relationship between the rounded lower support and the inner wall of the vacuum pipe.

[0023] Figure 5 It is a step-by-step diagram of the installation process (including initial installation, welding, board removal and debugging).

[0024] Figure 6 The following is a comparison diagram of the multi-section and integral designs of the lower support; among them, (a) is a schematic diagram of the multi-section structure, and (b) is a schematic diagram of the integral structure.

[0025] Figure 7 This is the schematic diagram of the adjustment screw to fine-tune the system posture.

[0026] Figure 8 This is a decomposition diagram of the installation steps after the lower base is welded and fixed; among them, (a) is a schematic diagram of the steps for removing the flat adapter plate, and (b) is a schematic diagram of the steps for connecting the guide rail assembly to the flat adapter plate.

[0027] Markings in the figure: 1. Fixing bolt, 2. Adjusting nut, 3. Vacuum pipe, 4. External support fixture, 5. "Cat's eye" retroreflector, 6. Linear motor module, 7. Planar adapter plate, 8. Rounded bottom bracket, 9. External pipe support screw, 10. Optical plane, 11. Fixing screw, 12. Adjustment screw. DETAILED DESCRIPTION

[0028] The pipeline support structure of the vacuum delay line system of the long baseline optical interferometer proposed by the present invention is described in detail below with reference to the accompanying drawings.

[0029] The pipeline support structure of the present invention is entirely housed within the long-baseline optical interferometer chamber, requiring a certain degree of vacuum within the pipeline. The "cat's eye" retroreflector is driven by a linear motor module, which requires a certain degree of flatness for its installation, placing certain demands on the installation and adjustment of the internal support structure within the pipeline. To meet the operational requirements of the "cat's eye" retroreflector 5 in high-precision applications, the complete support structure ensures that the linear motor module 6 can be installed with high flatness within a vacuum environment, guaranteeing the reflector's linear operation and stability.

[0030] like Figure 1-2 As shown, the pipeline support structure for a vacuum delay line system of a long-baseline optical interferometer according to the present invention mainly includes: a vacuum pipeline 3 mounted on an optical plane 10, a "cat's eye" retroreflector 5 and its linear motor module 6 located inside the vacuum pipeline 3, an internal support assembly disposed inside the vacuum pipeline 3, and an external support assembly disposed outside the vacuum pipeline. The motor of the linear motor module achieves linear motion through a guide rail system, and the optical plane 10 is used to improve the optical stability and operating accuracy of the entire device. Among them:

[0031] The inner support assembly is used to reliably fix the guide rail system with high flatness requirements inside the vacuum pipeline while maintaining adjustability and installation flexibility. The inner support assembly mainly consists of two parts: a flat adapter plate 7 and a rounded bottom bracket 8. Figure 3 As shown, the flat adapter plate and the rounded bottom bracket cooperate to fix the guide rail system inside the vacuum pipe and ensure the high flatness installation requirements required for the operation of the linear motor. The flat adapter plate 7 and the rounded bottom bracket 8 are integrally installed inside the vacuum pipe 3, as shown in FIG. Figure 4 shown.

[0032] Among them, the flat adapter plate 7 is used to connect the guide rail mounting surface and the circular inner wall of the vacuum pipeline, and has a flatness adjustment function; at the same time, the adapter plate acts as a welding template during the welding process to ensure that the relative positions between the two rounded lower brackets are consistent, thereby improving the overall accuracy of the system assembly. In this embodiment, the flat adapter plate 7 is connected to the guide rail system and fixed to the rounded lower bracket by screws. Specifically, it is a rectangular plate that can be flexibly modified according to the size of the guide rail. It is provided with a plurality of mounting holes. The hole positions are designed according to the actual guide rail system and the actual hole positions of the rounded lower bracket to adapt to different guide rail specifications and installation requirements. The flat adapter plate is used to provide the standard plane required for the guide rail installation, and at the same time has a fine-tuning function to achieve parallelism matching with the experimental platform.

[0033] Among them, the rounded lower base 8 is an arc-shaped structure with an arc radius of 500 mm. The arc diameter of the entire lower base is 1000 mm, which contacts and fits the inner wall of the vacuum pipeline. The upper side of the rounded lower base is a stepped, wedge-shaped or inclined structure, and the flat adapter plate is connected to the rounded lower bases on both sides through this structure. By replacing the combination of components with different thicknesses or angles, the support height can be adjusted within the millimeter range, thereby controlling the vertical position of the center of the optical path. For example, for every 1 mm change in the thickness of the support plate, the optical axis height can change by 1 mm, which is convenient for matching with different optical systems. The lower base can be designed as a multi-segment splicing structure, such as Figure 6 As shown in (a), it can also be set as an integrated molding structure according to process requirements, such as Figure 6 By changing its geometric parameters (such as thickness and center height), the installation height of the entire support system relative to the vacuum pipeline can be flexibly adjusted.

[0034] like Figure 7 As shown, the positioning and flatness of the plane adapter plate 7 are adjusted by a fine-tuning assembly consisting of a fixing screw 11 and an adjusting screw 12 to ensure the stability and accuracy of its installation. Specifically, a plurality of groups of fine-tuning assemblies are arranged along the axial extension direction of the vacuum pipeline 3, and each group of fine-tuning assemblies includes a fixing screw 11 and an adjusting screw 12. The plane adapter plate 7 is provided with two threaded holes at the position of the same group of fine-tuning assemblies, and the rounded lower base support is provided with a threaded hole and a height-limiting hole at positions corresponding to the two threaded holes. The fixing screw 11 connects and fixes the plane adapter plate 7 and the rounded lower base support 8 as a whole through threaded cooperation, and the adjusting screw 12 is threadedly cooperated with the plane adapter plate 7, and at the same time, the adjusting screw 7 abuts against the height-limiting hole on the rounded lower base support 8. The posture of the system can be adjusted by cooperating with the fixing screw 11 and the adjusting screw 12. The adjusting screw cooperates with the height-limiting hole, and by adjusting the slight displacement of the end of the support structure, the pitch or eccentric angle of the guide rail support surface is changed, so as to achieve precise alignment of the guide rail system with the external optical platform. As shown Figure 3 and Figure 7As shown in the figure, the fixing screw is used to ensure the stable position, while the adjusting screw allows multi-dimensional adjustment before locking. The system attitude error can be controlled within 0.1°, effectively improving the alignment accuracy and stability of the system.

[0035] The installation method of the internal support assembly includes assembly positioning, welding fixation, disassembly of the base plate, guide rail installation, and final adjustment. The system adopts a step-by-step assembly process. Pre-adjustment before welding ensures the parallelism of the guide rail and the experimental platform. After welding, detachable connection and fine-tuning are achieved. The installation method specifically includes the following steps: pre-install and fix the flat adapter plate with the rounded bottom bracket by screws to form an integral structure; fix the integral structure to the inner wall of the vacuum pipe by spot welding, such as Figure 5 As shown in FIG, during the welding process, the parallelism between the plane adapter plate and the external reference fixture is maintained with the experimental platform. During the welding process, the installation height of the entire structure relative to the vacuum pipeline can be changed by changing the width dimension of the plane adapter plate or by changing the depth of the stepped cross-section of the bottom support under the rounded corner, thereby achieving the adjustability of the optical path height. Figure 8 As shown in the figure, after welding is completed, remove the plane adapter plate to make room for the guide rail installation; connect the guide rail assembly to the plane adapter plate and tighten it according to the reserved holes; as shown in the figure Figure 7 As shown, the system's posture and guide rail flatness are fine-tuned using the base support fixing screws and adjustment screws. The fixing screws mate with the rounded through-holes in the lower base support to ensure overall system stability. The adjustment screws mate with the height-limiting holes in the lower base support, generating support force at the connection with the height-limiting holes to achieve fine-tuning of the system's posture. This support structure effectively utilizes the geometric properties of the circular tube, employing arc contact to enhance support stability. Furthermore, a modular design, based on traditional welding fixation, facilitates subsequent adjustments and maintenance.

[0036] The external support assembly consists of a pair of symmetrical structures connected by a clearance fit. Specifically, it includes two symmetrically arranged external support fixtures 4. The external support fixtures 4 are connected to the optical plane 10 through a clearance fit, providing both position limiting and fine-tuning functions. The external support fixtures 4 comprise a curved plate portion and a straight plate portion. The curved plate portion conforms to the outer wall of the vacuum pipe. The upper ends of the two curved plates are secured together by a clearance fit using a fixing bolt 1 and an adjustment nut 2. The fixing bolt and adjustment nut cooperate to adjust the gap between the upper ends of the two curved plates. The curved plate portion transitions vertically and tangentially into the straight plate portion. The lower end of the straight plate portion is clearance-fitted with the optical plane 10 and secured by an external support screw 9. The external support screw 9 adjusts the gap between the straight plate portion and the optical plane, enabling secure positioning and precise adjustment of the vacuum pipe's position. This structure leverages the geometric properties of the circular pipe, providing stable support while enhancing the overall system's adjustability and load-bearing strength. In this invention, all components are designed to be detachable, utilizing universal threaded holes, locating pins, and slideways. This allows for independent connection and positioning of the flat adapter plate and lower bracket during installation. The guide rails utilize a "position-first, then secure" structure, enabling rapid on-site component replacement and local maintenance without disassembly, significantly improving system assembly efficiency and reducing maintenance requirements.

[0037] In summary, the present invention proposes an innovative improvement scheme based on the traditional circular tube support structure, utilizing the basic properties of the circle to improve strength and enhance adjustability. It has the advantages of reasonable structure, installable and adjustable, high installation precision and strong vacuum adaptability. By introducing a planar adapter plate with adjustment function, a clearance-fit support assembly and an adjustable fastening screw, it achieves stable support and flexible adjustment of the pipeline under high-precision requirements and vacuum environment, supports the flatness installation of the linear motor module, is suitable for astronomical optical interferometry systems with strict requirements on flatness and stability, and can effectively solve the support problem of the vacuum pipeline of the vacuum delay line of the long-baseline optical interferometer.

[0038] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent replacements, and improvements made within the spirit and principles of the present invention shall be included in the scope of protection of the present invention.

Claims

1. A pipeline support structure for a long baseline optical interferometer vacuum delay line system, characterized in that: include: Vacuum line mounted on an optical plane; A "cat's eye" retroreflector and its linear motor module located inside the vacuum tube; An internal support assembly is arranged inside the vacuum pipeline, and the internal support assembly includes a flat adapter plate and a rounded lower base. The flat adapter plate is connected to the guide rail system of the linear motor module and is fixed to the rounded lower base through a fine-tuning assembly. The lower side of the rounded lower base is an arc-shaped structure, which is fixed to the inner wall of the vacuum pipeline.

2. The pipeline support structure according to claim 1, characterized in that: The upper side of the rounded lower base is a stepped structure, and the plane adapter plate is connected to the rounded lower base on both sides through the stepped structure.

3. The pipeline support structure according to claim 1, characterized in that: The fine-tuning assembly includes a fixing screw and an adjusting screw. The fixing screw connects and fixes the plane adapter plate and the rounded lower base bracket into one piece through threaded engagement. The adjusting screw is threadedly engaged with the plane adapter plate, and the adjusting screw abuts against the height limit hole on the rounded lower base bracket.

4. The pipeline support structure according to claim 1, characterized in that: The rounded lower base is an integrated structure or a multi-section spliced structure.

5. The pipeline support structure according to claim 1, characterized in that: The installation method of the inner support component includes the following steps: first, connecting the flat adapter plate with the rounded lower base to form a pre-installed component one; then, fixing the pre-installed component one to the inner wall of the vacuum pipeline through the arc structure on the lower side of the rounded lower base; then, removing the flat adapter plate, and connecting the flat adapter plate with the guide rail system to form a pre-installed component two; finally, completing the posture adjustment of the pre-installed component two through the fine-tuning component.

6. The pipeline support structure according to claim 5, characterized in that: By changing the dimension of the planar adapter plate in the width direction or by changing the thickness of the planar adapter plate, the installation height of the pre-installed component 1 relative to the vacuum pipeline is changed, thereby adjusting the height of the optical axis of the optical path.

7. The pipeline support structure according to claim 5, characterized in that: First, the entire structure of the pre-assembled component is fixed to the inner wall of the vacuum pipeline by spot welding. Then, during the welding process, a plane adapter plate and an external reference fixture are used to maintain the parallelism between the pre-assembled component and the optical plane.

8. The pipeline support structure according to claim 1, characterized in that: It also includes an external support assembly, which includes two external support fixings symmetrically installed outside the vacuum pipeline. The external support fixings include a bent plate portion and a straight plate portion. The bent plate portion fits the outer wall of the vacuum pipeline. The upper ends of the two bent plate portions are fixedly connected by clearance fit. The bent plate portion transitions to the straight plate portion along the vertical tangent, and the lower end of the straight plate portion is fixed to the optical plane.

9. The pipeline support structure according to claim 8, characterized in that: A fixing bolt is passed through the connection between the upper ends of the two bent plate parts, and the fixing bolt cooperates with the adjusting nut to adjust the size of the gap between the upper ends of the two bent plate parts.

10. The pipeline support structure according to claim 8, characterized in that: The straight plate portion and the optical plane are connected by the pipeline external support screw, and the gap between the external support fixing piece and the optical plane is adjusted by the pipeline external support screw.

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