Carbon fiber main support structure for large aperture and long focal length coaxial space camera

Abstract

The present invention relates to the technical field of space optical cameras, and in particular to a carbon fiber main support structure of a large-aperture, long-focal-length coaxial space camera, comprising a center ring, an upper tube, a middle tube, a support frame and a bottom tube; wherein the upper tube, the middle tube, the support frame and the bottom tube adopt a carbon fiber structure; the center ring is connected in the upper tube for placing an external space camera; the upper tube and the bottom tube are connected through a support frame; the middle tube is a thin-walled positive conical tube, covering the support frame, and connected to the upper tube and the bottom tube. The combined support form of the carbon fiber tube and the carbon fiber rod in the support structure of the present invention can ensure that the structure as a whole has a strong ability to resist gravity deformation, and the near-zero expansion ply design of the carbon fiber structure enables the long-focal-length space camera to have better temperature adaptability.

Description

Technical Field

[0001] The invention relates to the technical field of space optical cameras, and in particular to a carbon fiber main supporting structure of a large-aperture and long-focal-length coaxial space camera. Background Art

[0002] In the design of the secondary mirror support structure of large-aperture and long-focal-length coaxial optical cameras, near-zero expansion carbon fiber is a commonly used material in order to reduce the sensitivity of optical performance to temperature.

[0003] The existing carbon fiber support structures are mainly of two types: cylindrical and truss rod types. The cylindrical structure is complex to form, and the cost of using high-performance carbon fiber as the molding material is too expensive. It is difficult to achieve a good design result by using low-performance carbon fiber materials. The cylindrical structure is generally a thin-walled structure. If the wall is too thin, the stability is poor, and if the wall is too thick, it is not conducive to lightweight.

[0004] The truss rod structure has a simple process and low manufacturing cost. High-performance carbon fiber materials can be used to improve the structural rigidity. However, a single truss rod has a poor stray light suppression effect. In order to control excess stray light from entering the system and affecting the imaging performance, a longer sunshade is added to the periphery of the truss rod. The separated sunshade has a counter-effect on suppressing the gravity deformation of the secondary mirror. Summary of the invention

[0005] In order to solve the above problems, the present invention provides a carbon fiber main support structure for a large-aperture and long-focal-length coaxial space camera, which supports the secondary mirror structure by using truss rods made of high-performance carbon fiber materials and carbon fiber tubes made of low-performance carbon fiber materials, and ensures near-zero expansion of the support structure through reasonable layer design, thereby improving the adaptability of the large-aperture and long-focal-length space camera to different temperatures.

[0006] The carbon fiber main support structure of a large-aperture long-focal-length coaxial space camera provided by the present invention comprises a center ring, an upper tube, a middle tube, a support frame and a bottom tube; wherein the upper tube, the middle tube, the support frame and the bottom tube adopt a carbon fiber structure; the center ring is connected in the upper tube for placing an external space camera; the upper tube and the bottom tube are connected through the support frame; the middle tube is a thin-walled positive conical tube, which covers the support frame and is connected to the upper tube and the bottom tube.

[0007] Furthermore, the upper cylinder includes an inner ring, an outer ring, a support member and no less than 3 support plates; the support member is used to support the center ring; the support member is connected to the inner ring and is connected to the outer ring through the support plate; the wall thickness of the outer ring is smaller than the wall thickness of the inner ring, and ribs with the same wall thickness as the outer ring are arranged on the inner wall of the outer ring.

[0008] Furthermore, the support frame includes no less than 6 thin-walled truss rods, and the two ends of each thin-walled truss rod are respectively connected to the outer ring and the bottom tube through titanium alloy joints; the two ends of each thin-walled truss rod are staggered and connected to adjacent thin-walled truss rods through titanium alloy joints, so that the support frame has a conical structure consistent with the shape of the middle tube.

[0009] Furthermore, the number of thin-walled truss rods satisfies 6+6n (n=1, 2, 3, ...).

[0010] Furthermore, the two ends of the middle tube are connected to the outer ring and the bottom tube respectively; the wall thickness of the middle tube is 0.8mm-1.5mm, and ribs consistent with the wall thickness of the middle tube are arranged on the inner wall of the middle tube.

[0011] Furthermore, the bottom tube is a thin-walled tube, and ribs consistent with the wall thickness of the bottom tube are distributed inside the bottom tube; inlays for installing the support frame are evenly embedded inside the bottom tube along the circumferential direction, and the positions of the inlays correspond to the fulcrums of the bottom tube.

[0012] Furthermore, the center ring and the insert are made of high volume fraction aluminum-based silicon carbide material.

[0013] Furthermore, the temperature expansion coefficient of the middle tube and the support frame is less than 0.5×10 -6 / k.

[0014] Compared with the prior art, the present invention can achieve the following beneficial effects:

[0015] The present invention adopts truss rods made of high-performance carbon fiber materials and carbon fiber tubes made of low-performance carbon fiber materials to jointly support the secondary mirror structure, which not only saves costs but also achieves high rigidity of the structure. At the same time, through reasonable layer design, the design of near-zero expansion of the support structure can be ensured, which can make the large-aperture and long-focal-length space camera have better adaptability to temperature. BRIEF DESCRIPTION OF THE DRAWINGS

[0016] Figure 1 is an overall structural diagram of a carbon fiber main support structure of a large-aperture and long-focal-length coaxial space camera provided according to an embodiment of the present invention;

[0017] Figure 2 is a structural diagram of an upper cylinder provided according to an embodiment of the present invention;

[0018] Figure 3 is a structural diagram of a support frame provided according to an embodiment of the present invention;

[0019] Figure 4 is a structural diagram of a bottom tube provided according to an embodiment of the present invention.

[0020] Reference numerals: center ring 1 , inner ring 2 , outer ring 3 , support member 4 , support plate 5 , thin-walled truss rod 6 , titanium alloy joint 7 , middle tube 8 , bottom tube 9 , inlay 10 . DETAILED DESCRIPTION

[0021] In order to make the purpose, technical solution and advantages of the present invention more clearly understood, the present invention is further described in detail below in conjunction with the accompanying drawings and specific embodiments. It should be understood that the specific embodiments described herein are only used to explain the present invention and do not constitute a limitation of the present invention.

[0022] The carbon fiber main support structure of the large-aperture and long-focal-length coaxial space camera provided by the embodiment of the present invention supports the secondary mirror structure by using truss rods made of high-performance carbon fiber materials and carbon fiber tubes made of low-performance carbon fiber materials. The near-zero expansion of the support structure is ensured through reasonable layer design, thereby improving the adaptability of the large-aperture and long-focal-length space camera to different temperatures and saving costs.

[0023] Figure 1 The overall structure of the carbon fiber main support structure of a large-aperture and long-focal-length coaxial space camera provided according to an embodiment of the present invention is shown; Figure 2 The structure of the upper cylinder provided according to an embodiment of the present invention is shown.

[0024] like Figure 1 and Figure 2 As shown, the carbon fiber main support structure of the large-aperture and long-focal-length coaxial space camera provided by an embodiment of the present invention includes a center ring 1, an upper tube, a support frame, a middle tube 8 and a bottom tube 9, wherein the upper tube includes an inner ring 2, an outer ring 3, a support member 4 and no less than 3 support plates 5.

[0025] The center ring 1 is supported on the support member 4, which is circumscribed to the inner ring 2, and the inner ring 2 is connected to the outer ring 3 through the support plate 5. In the embodiment of the present invention, the support member 4 is a thin-walled regular triangle structure, and one end of the three support plates 5 is connected to the three vertices of the support member 4, and the other end is connected to the three supporting points on the outer ring 3. The wall thickness of the outer ring 3 is less than that of the inner ring 2, and the two ends of the outer ring 3 are turned inward, and ribs with the same wall thickness as the outer ring 3 are arranged on the inner wall of the outer ring 3.

[0026] The middle tube 8 is a thin-walled positive conical tube with a wall thickness of 0.8mm-1.5mm, covering the support frame and connected to the outer ring 3 and the bottom tube 9. Both ends of the middle tube 8 are turned inward, and ribs consistent with the wall thickness of the middle tube 8 are arranged on the inner wall of the middle tube 8. In the embodiment of the present invention, the wall thickness of the middle tube 8 is designed to be 1mm.

[0027] Figure 3 The structure of a support frame provided according to an embodiment of the present invention is shown.

[0028] like Figure 1 and Figure 3 As shown, the support frame includes no less than 6 thin-walled truss rods 6, and both ends of each thin-walled truss rod 6 are connected to adjacent thin-walled truss rods 6 through titanium alloy joints 7, and both ends of each thin-walled truss rod 6 are respectively connected to the outer ring 3 and the bottom tube 9 through titanium alloy joints 7. Both ends of each thin-walled truss rod 6 are staggered and connected to adjacent thin-walled truss rods 6 through titanium alloy joints 7, so that the support frame is a tapered structure consistent with the shape of the middle tube 8.

[0029] Specifically, the number of the thin-walled truss rods 6 satisfies 6+6n (n=1, 2, 3, ...). In the embodiment of the present invention, n=6, that is, 12 thin-walled truss rods 6 are used.

[0030] In the embodiment of the present invention, the titanium alloy joint 7 is bonded to both ends of the thin-walled truss rod 6, and the two ends of each thin-walled truss rod 6 are alternated by 30 degrees. The titanium alloy joint 7 is a titanium alloy joint with a stepped shaft, and the stepped shaft is a thin-walled hollow shaft and the height of the stepped shaft is equal to the diameter. The end with a smaller diameter in the support frame is connected to the outer ring 3 through the titanium alloy joint 7 and corresponds to the three fulcrums on the outer ring 3; the end with a larger diameter in the support frame is connected to the bottom tube 9 through the titanium alloy joint 7.

[0031] Figure 4 The structure of the bottom tube provided according to an embodiment of the present invention is shown.

[0032] like Figure 1 and Figure 4 As shown, the bottom tube 9 is a thin-walled tube, and the thickness of the bottom tube 9 is less than one tenth of the diameter of the bottom tube 9. Both ends of the bottom tube 9 are turned inward, and ribs with the same wall thickness as the bottom tube 9 are arranged on the inner wall of the bottom tube 9. Inlays 10 for connecting the support frame are evenly embedded in the inside of the bottom tube 9 along the circumferential direction, and the position of the inlay 10 corresponds to the fulcrum of the bottom tube 9. One end of the support frame passes the titanium alloy joint 7 through the one side of the bottom tube 9 and is then installed in the inlay 10, thereby completing the connection between the support frame and the bottom tube 9.

[0033] Furthermore, the center ring 1 and the inlay 10 are made of high volume fraction aluminum-based silicon carbide material, the upper tube, the support frame, the middle tube 8 and the bottom tube 9 are made of carbon fiber structure, and the temperature expansion coefficient of the support frame and the middle tube 8 is less than 0.5×10 -6 / k.

[0034] In the embodiment of the present invention, the upper tube, the middle tube 8 and the bottom tube 9 are all made of M40 carbon fiber material, and the support frame is made of M55 carbon fiber material.

[0035] The carbon fiber main support structure of the large-aperture and long-focal-length coaxial space camera provided by the embodiment of the present invention can achieve a gravity displacement of the secondary mirror of less than 0.02 mm and a rotation angle of less than 3″ for a space optical system with an aperture of 1 m and a focal length of 10 m.

[0036] The above specific implementations do not constitute a limitation on the protection scope of the present invention. It should be understood by those skilled in the art that various modifications, combinations, sub-combinations and substitutions can be made according to design requirements and other factors. Any modification, equivalent substitution and improvement made within the spirit and principle of the present invention should be included in the protection scope of the present invention.

Claims

1. A carbon fiber main support structure for a large-aperture and long-focal-length coaxial space camera, characterized in that: It includes a center ring, an upper tube, a middle tube, a support frame and a bottom tube; wherein the upper tube, the middle tube, the support frame and the bottom tube are made of carbon fiber structure; The center ring is connected to the upper tube and is used to place an external space camera; The upper cylinder is connected to the bottom cylinder via the support frame; The middle tube is a thin-walled positive conical tube, covering the support frame and connected to the upper tube and the bottom tube; The upper cylinder comprises an inner ring, an outer ring, a support member and no less than 3 support plates; The support member is used to support the center ring; the support member is externally connected to the inner ring and is connected to the outer ring through the support plate; The wall thickness of the outer ring is smaller than that of the inner ring, and ribs having the same thickness as that of the outer ring are arranged on the inner wall of the outer ring; The support frame includes no less than 6 thin-walled truss rods, and the two ends of each thin-walled truss rod are respectively connected to the outer ring and the bottom tube through titanium alloy joints; the two ends of each thin-walled truss rod are staggered and connected to adjacent thin-walled truss rods through the titanium alloy joints, so that the support frame is a tapered structure consistent with the shape of the middle tube; The end of the support frame with a smaller diameter is connected to the outer ring through the titanium alloy joint, and the end of the support frame with a larger diameter is connected to the bottom tube through the titanium alloy joint; The upper tube, the middle tube and the bottom tube are all made of M40 carbon fiber material, and the support frame is made of M55 carbon fiber material.

2. The carbon fiber main support structure of the large-aperture and long-focal-length coaxial space camera according to claim 1 is characterized in that: The number of the thin-walled truss rods satisfies 6+6n (n=1, 2, 3, ...).

3. The carbon fiber main support structure of the large-aperture and long-focal-length coaxial space camera according to claim 1 is characterized in that: The two ends of the middle tube are connected to the outer ring and the bottom tube respectively; the wall thickness of the middle tube is 0.8mm-1.5mm, and ribs consistent with the wall thickness of the middle tube are arranged on the inner wall of the middle tube.

4. The carbon fiber main support structure of the large-aperture and long-focal-length coaxial space camera according to claim 1 is characterized in that: The bottom tube is a thin-walled tube, and ribs having the same wall thickness as the bottom tube are distributed inside the bottom tube; inlays for installing the support frame are evenly embedded inside the bottom tube along the circumferential direction, and the positions of the inlays correspond to the fulcrums of the bottom tube.

5. The carbon fiber main support structure of the large-aperture and long-focal-length coaxial space camera according to claim 4 is characterized in that: The center ring and the insert are made of high volume fraction aluminum-based silicon carbide material.

6. The carbon fiber main support structure of the large-aperture and long-focal-length coaxial space camera according to claim 1, characterized in that: The temperature expansion coefficient of the middle tube and the support frame is less than 0.5×10 -6 / k.

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