High-precision and high-stability hollow angle mirror and preparation method thereof

Abstract

The invention relates to a hollow angle mirror and a preparation method thereof, in particular to a high-precision and high-stability hollow angle mirror and a preparation method thereof, which are used for overcoming the defects of poor structural stability and poor environmental adaptability of the hollow angle mirror caused by flaws due to the fact that the existing hollow angle mirror depends on bonding or structural design. According to the high-precision and high-stability hollow angle mirror and the preparation method thereof, through a metal mirror processing technology, a multi-layer connection and fastening structure and a precision adjustment scheme of multi-degree-of-freedom trimming, the defect that traditional glue cannot be adjusted and repaired is overcome; and the problems of insufficient vibration resistance and impact resistance of an existing metal hollow angle mirror scheme are solved, so that the comprehensive performance of the hollow angle mirror is greatly improved, and the hollow angle mirror can be used in complex environments such as aerospace and the like.

Description

Technical Field

[0001] The invention relates to a hollow corner mirror and a preparation method thereof, and in particular to a high-precision and high-stability hollow corner mirror and a preparation method thereof. Background Art

[0002] Hollow corner mirror, also known as hollow corner cone prism, is shaped like an inverted triangular corner cone structure with a hollow center. No matter from which direction the light hits the surface of the hollow corner cone, the light on any mirror surface can be reflected and returned along the original propagation direction. This feature makes hollow corner mirrors widely used in many fields, including optical communications, laser ranging, optical measurement, optical positioning, automotive lighting, scientific research, and aerospace.

[0003] At present, there are two main technical paths used in the development of hollow corner mirrors at home and abroad:

[0004] (1) Adhesion or bonding technology of glass substrate: This technical path usually uses glass material as the substrate for epoxy bonding or hydrogen-oxygen molecular catalytic bonding. Representative products include the Apollo 170mm caliber retroreflector developed by NASA and placed on the moon, and the 170mm hollow corner mirror developed by the Tianqin Gravitational Physics Research Center of my country for the next generation of lunar distance exploration. Both products use the technical approach of epoxy bonding and hydrogen-oxygen molecular catalytic bonding.

[0005] (2) Mechanical structure adjustment technology of metal substrate or silicon carbide substrate: This path uses metal substrate or silicon carbide substrate to develop large-aperture hollow corner mirrors by mechanical structure adjustment. Typical representatives include the large-aperture hollow corner mirrors in IASI-FTS and the large-aperture hollow corner mirrors made of aluminum-based materials used by the Institute of Technical Physics.

[0006] Although the above technical paths have achieved certain results in the development of large-aperture hollow corner mirrors, there are still some problems and shortcomings that need to be solved:

[0007] (1) The hollow corner mirrors bonded by traditional gluing process and hydrogen-oxygen molecular bonding process have poor performance in terms of structural stability. It is difficult to connect the hollow corner mirrors made of glass materials and structural parts based on gluing, while the direct bonding of metal and glass will cause changes in the surface accuracy of the plane mirror.

[0008] (2) In the above design, the installation accuracy is adjusted by screws on the bottom surface, and the structural connection between the installation interface and the adjustment screw is not isolated, which is easily affected by vibration, resulting in poor overall impact resistance. Summary of the invention

[0009] The purpose of the present invention is to solve the shortcomings of the existing hollow corner mirrors that rely on bonding or have structural design defects, resulting in poor structural stability and poor environmental adaptability, and to provide a high-precision and high-stability hollow corner mirror and a preparation method thereof.

[0010] In order to solve the deficiencies of the above-mentioned prior art, the present invention provides the following technical solutions:

[0011] A high-precision and high-stability hollow corner mirror, which is special in that it includes a main body, three adapter plates and a metal support assembly;

[0012] The main body is used to reflect incident light so that it can return along the original path. The main body includes three metal mirrors connected perpendicularly to each other in pairs; the back of each metal mirror is provided with an adapter plate through a plurality of first screws, and an adhesive is provided between the metal mirror and the corresponding adapter plate; the tail of each first screw passes through a connection hole provided on the adapter plate and is fixed to the back of the metal mirror, and a gap is maintained between the head of the first screw and the adapter plate in its own axial direction; the connection hole is a through hole;

[0013] The metal support assembly is prepared by using an integrated manufacturing technology. The structure of the metal support assembly is adapted to the main body. The metal support assembly is connected to each adapter plate by a plurality of second screws. The tail of each of the second screws passes through the metal support assembly and is fixed in a screw hole set on the adapter plate. A gasket is set at the screw hole. The gasket is used to adjust the pitch and rotation posture of the corresponding metal mirror by adjusting its own thickness.

[0014] Furthermore, the depth of the screw hole is less than 1 / 2 of the thickness of the adapter plate, and stress relief grooves are provided on the inner circumferences of the screw hole and the connecting hole.

[0015] Furthermore, the material of the adapter plate is consistent with that of the metal mirror.

[0016] Furthermore, two side edges of each of the metal mirrors are in contact with the front sides or side edges of the other two metal mirrors respectively.

[0017] A method for preparing the above-mentioned high-precision and high-stability hollow corner mirror is special in that it comprises the following steps:

[0018] Step 1: According to the design specifications, three metal mirrors and three adapter plates respectively matching the backs of the three metal mirrors are manufactured, and a plurality of connection holes and a plurality of screw holes are set on each adapter plate;

[0019] Step 2, bonding the back side of each metal mirror to an adapter plate by means of an adhesive, and fixing them by means of three first screws;

[0020] Step 3: Prepare the metal support assembly using integrated manufacturing technology to ensure that its structure is compatible with the main structure of the hollow corner mirror;

[0021] Step 4: Connect each adapter plate to the metal support assembly through a plurality of second screws, and place gaskets at the screw holes to obtain a hollow corner mirror preform;

[0022] Step 5: adjusting the pitch and rotation positions of each metal mirror by trimming the thickness of the gasket, thereby adjusting the light beam emission parallel angle accuracy of the hollow corner mirror preform;

[0023] Step 6, detect the stress deformation of each metal mirror and the corresponding adapter plate, and determine whether the metal mirror and the corresponding adapter plate have deformed beyond the allowable tolerance. If not, the preparation of the high-precision and high-stability hollow corner mirror is completed; if so, return to step 5 until the deformation does not exceed the allowable tolerance, and the preparation of the high-precision and high-stability hollow corner mirror is completed.

[0024] Furthermore, the step 1 is specifically as follows:

[0025] Step 1.1, according to the design specifications, manufacture three metal mirrors, the size and shape of each metal mirror must meet the requirements of the inverted triangular pyramid structure, and ensure that its side can be in close contact with the front or side of the other two metal mirrors;

[0026] Step 1.2, select the material consistent with the metal mirror material to manufacture three adapter plates that match the backs of the three metal mirrors respectively, and set multiple connection holes and multiple screw holes on each adapter plate. The depth of the screw hole should be less than 1 / 2 of the thickness of the adapter plate.

[0027] Furthermore, in step 6, the stress deformation of each metal mirror and the corresponding adapter plate is detected as follows:

[0028] Step 6.1. Visually check whether there are obvious deformations or cracks on the surfaces of the metal mirror and the corresponding adapter plate. Touch with your fingers to check whether there are any uneven or loose places on the connection between the metal mirror and the corresponding adapter plate.

[0029] Step 6.2: Use a high-precision level or laser level to check the surface flatness of the metal mirror to ensure that it is within the allowable tolerance range;

[0030] Step 6.3, use a laser interferometer to perform interference test on the surface of the metal mirror to detect whether there is slight deformation on the surface; send a parallel light beam to the metal mirror, and determine whether there is stress deformation of the metal mirror by detecting the parallelism of the reflected light beam;

[0031] Step 6.4, place the hollow corner mirror in a constant temperature box, perform a temperature cycle test within a certain range, and use a stress analyzer to detect the deformation of the metal mirror and the corresponding adapter plate at different temperatures to ensure that stress deformation exceeding the tolerance is not caused during the temperature change process;

[0032] Step 6.5: Adjust the pitch and rotation position of the metal mirror by trimming the gasket, and perform the precision test of the light beam emission parallel angle again to ensure that the adjusted metal mirror meets the design requirements.

[0033] Step 6.6: Comprehensively analyze all test data to ensure that the stress and deformation in all test steps are within the allowable range.

[0034] Compared with the prior art, the present invention has the following beneficial effects:

[0035] (1) The present invention provides a high-precision and high-stability hollow corner mirror. By using metal mirror processing technology, multi-layer connection and fastening structure, and multi-degree-of-freedom trimming and precision adjustment scheme, the present invention avoids the disadvantages of traditional gluing that it cannot be adjusted and repaired. It also optimizes the problems of insufficient vibration and impact resistance of existing metal hollow corner mirror schemes, thereby greatly improving the comprehensive performance of the hollow corner mirror and ensuring that the hollow corner mirror can be used in complex environments such as aerospace.

[0036] (2) Compared with the traditional hollow corner mirror based on the gluing process, the present invention adopts a metal mirror and fastens it with screws, which has better structural stability, better vibration resistance and environmental adaptability.

[0037] (3) Compared with the hollow corner mirror prepared by the traditional gluing process, which cannot be changed after being formed once, the present invention has the ability to be adjusted multiple times. Even if the accuracy is reduced under extreme conditions, it can still be used through secondary adjustment to ensure the parallelism accuracy of the incident light of the hollow corner mirror. Therefore, the present invention has stronger repeatable adjustment ability and environmental adaptability.

[0038] (4) Compared with the current metal-based hollow corner mirror design solutions at home and abroad, the present invention adopts a three-layer connection structural fixing method to distribute the stress of screw tightening to the middle adapter plate, thereby ensuring the surface accuracy of the metal mirror.

[0039] (5) The present invention provides a method for assembling and adjusting a hollow corner mirror with high precision and high stability. During the process, no damage will occur to components, which will affect subsequent corrections and secondary adjustment. Therefore, the requirements for the adjustment platform and equipment are more relaxed, the adjustment difficulty is smaller, and the yield rate of the hollow corner mirror is also higher. BRIEF DESCRIPTION OF THE DRAWINGS

[0040] Figure 1 It is a structural schematic diagram of an embodiment of a high-precision and high-stability hollow corner mirror of the present invention;

[0041] Figure 2 The isometric view of the main body and the adapter plate in the embodiment of the present invention Figure 1 ;

[0042] Figure 3 The isometric view of the main body and the adapter plate in the embodiment of the present invention Figure 2 (first screw not shown);

[0043] Figure 4 The present invention is a flow chart of a method for preparing a high-precision and high-stability hollow corner mirror.

[0044] The following are the descriptions of the reference numerals:

[0045] 1-metal mirror; 2-adapter plate; 3-metal support assembly; 4-gasket; 5-connection hole. DETAILED DESCRIPTION

[0046] The present invention is further described below in conjunction with the accompanying drawings and exemplary embodiments.

[0047] Reference Figures 1 to 3 A high-precision and high-stability hollow corner mirror includes a main body, three adapter plates 2 and a metal support component 3.

[0048] The main body is used to reflect the incident light so that it can return along the original path, and the main body includes three metal mirrors 1 connected vertically to each other. Two side edges of each metal mirror 1 are in contact with the front or side edges of the other two metal mirrors 1 respectively, but are not fastened / adhered.

[0049] Reference Figure 2 , Figure 3 , an adapter plate 2 is set on the back of each metal mirror 1 through three first screws, and the tail of each first screw passes through the connection hole 5 set on the adapter plate 2 and is fixed to the back of the metal mirror 1. An adhesive is set between the metal mirror 1 and the corresponding adapter plate 2; the fastening between the metal mirror 1 and the adapter plate 2 is achieved by gluing the contact surface, thereby ensuring a reliable connection between the two; in order to avoid stress deformation of the metal mirror 1, a stress relief groove is set on the inner periphery of the connection hole 5 on the adapter plate 2, and the connection hole 5 is a through hole. The first screw is used to further strengthen the connection stability between the two on the basis of bonding. The material of the adapter plate 2 is consistent with that of the metal mirror 1, thereby ensuring that the metal mirror 1 and the adapter plate 2 have the same deformation trend when the temperature changes, eliminating the stress deformation caused by the inconsistent thermal expansion and contraction of different materials due to temperature changes.

[0050] Reference Figure 1The metal support assembly 3 is prepared by integrated manufacturing technology. The structure of the metal support assembly 3 is adapted to the main body. The metal support assembly 3 is connected to each adapter plate 2 by three second screws. After the tail of each second screw passes through the metal support assembly 3, it is fixed in the screw hole set on the adapter plate 2. The depth of each screw hole is less than 1 / 2 of the thickness of the adapter plate 2. A stress relief groove is set on the inner circumference of the screw hole to ensure that the stress deformation caused by the connection between the metal support assembly 3 and the adapter plate 2 is as small as possible. Through the connection between the adapter plate 2 and the metal support structure, the stress deformation caused by the high-strength fastening directly on the metal mirror 1 is avoided, and the influence of the stress deformation on the metal mirror 1 is further reduced, thereby ensuring the surface accuracy of the hollow corner mirror and the imaging quality of the hollow corner mirror in the optical system.

[0051] A gasket 4 is provided at each screw hole, and the pitch and rotation posture of the corresponding metal mirror 1 can be adjusted by trimming the gasket 4, thereby adjusting the parallel angle accuracy of the light beam output of the hollow corner mirror. Compared with the traditional solution of only providing a single adjustment structure for each lens, each metal mirror 1 in the present invention has three adjustable structures (gaskets 4), which maximizes the accuracy of the parallel light input and output angles of the hollow corner mirror.

[0052] Reference Figure 4 A method for preparing the above-mentioned high-precision and high-stability hollow corner mirror comprises the following steps:

[0053] Step 1, preparation of the metal mirror 1 and the adapter plate 2;

[0054] Step 1.1, select metal materials with high stability and high precision, and manufacture three high-precision plane reflective metal mirrors 1 according to the design specifications; the size and shape of each metal mirror 1 must meet the requirements of the inverted triangular pyramid structure, ensuring that its side can be in close contact with the front or side of the other two metal mirrors 1 to prevent light leakage or stray light at the joints between the two metal mirrors 1;

[0055] Step 1.2, select the same material as the metal mirror 1 to manufacture three adapter plates 2 that match the back of the metal mirror 1; each adapter plate 2 should be pre-drilled with three connection holes 5 and three screw holes, and the depth of the screw holes should be less than 1 / 2 of the thickness of the adapter plate 2;

[0056] Step 2, connecting the metal mirror 1 and the adapter plate 2;

[0057] Select an adhesive suitable for metal materials for bonding the metal mirror 1 and the adapter plate 2;

[0058] The back side of each metal mirror 1 is bonded to an adapter plate 2 by an adhesive and fixed by three first screws. The first screws do not need to be tightened to avoid stress deformation of the metal mirror 1.

[0059] Step 3, preparation of metal support assembly 3;

[0060] The metal support assembly 3 is prepared by using an integrated manufacturing technology to ensure that its structure is compatible with the main structure of the hollow corner mirror;

[0061] Step 4: Overall assembly;

[0062] The adapter plate 2 is connected to the metal support assembly 3 by a second screw, and a gasket 4 is placed at the screw hole position to obtain a hollow corner mirror preform;

[0063] Step 5, adjusting the pitch and rotation posture of each metal mirror 1 by trimming the thickness of the gasket 4, thereby adjusting the light beam emission parallel angle accuracy of the hollow corner mirror preform;

[0064] Step 6, detecting the stress deformation of the metal mirror 1 and the corresponding adapter plate 2, and determining whether the metal mirror 1 and the corresponding adapter plate 2 are deformed beyond the allowable tolerance. If not, the preparation of the high-precision and high-stability hollow corner mirror is completed; if so, returning to step 5, until the deformation does not exceed the allowable tolerance, the preparation of the high-precision and high-stability hollow corner mirror is completed;

[0065] The stress deformation of the detection metal mirror 1 and the corresponding adapter plate 2 is specifically as follows:

[0066] Step 6.1, visually check whether there are obvious deformations or cracks on the surfaces of the metal mirror 1 and the corresponding adapter plate 2, and touch with your fingers to check whether there are any unevenness or looseness at the connection between the metal mirror 1 and the corresponding adapter plate 2;

[0067] Step 6.2, use a high-precision level or laser level to detect the surface flatness of the metal mirror 1 to ensure that it is within the allowable tolerance range;

[0068] Step 6.3, use a laser interferometer to perform interference test on the surface of the metal mirror 1 to detect whether there is slight deformation on the surface; send a parallel light beam to the metal mirror 11, and determine whether there is stress deformation of the metal mirror by detecting the parallelism of the reflected light beam;

[0069] Step 6.4, placing the hollow corner mirror in a constant temperature box, performing a temperature cycle test within a certain range, and using a stress analyzer to detect the deformation of the metal mirror 1 and the corresponding adapter plate 2 at different temperatures to ensure that stress deformation exceeding the tolerance is not caused during the temperature change process;

[0070] Step 6.5: Adjust the pitch and rotation position of the metal mirror 1 by trimming the gasket 4, and perform the precision test of the light beam emission parallel angle again to ensure that the adjusted metal mirror 1 meets the design requirements.

[0071] Step 6.6: Comprehensively analyze all test data to ensure that the stress and deformation in all test steps are within the allowable range.

Claims

1. A high-precision and high-stability hollow corner mirror, characterized in that: It comprises a main body, three adapter plates (2) and a metal support assembly (3); The main body is used to reflect incident light so that it can return along its original path, and the main body comprises three metal mirrors (1) connected perpendicularly to each other in pairs; the back of each metal mirror (1) is provided with an adapter plate (2) via a plurality of first screws, and an adhesive is provided between the metal mirror (1) and the corresponding adapter plate (2); after the tail of each first screw passes through a connection hole (5) provided on the adapter plate (2), it is fixed to the back of the metal mirror (1), and a gap is maintained between the head of the first screw and the adapter plate (2) in its own axial direction; the connection hole (5) is a through hole; The metal support component (3) is manufactured using an integrated manufacturing technology. The structure of the metal support component (3) is adapted to the main body. The metal support component (3) is connected to each adapter plate (2) via a plurality of second screws. The tail of each second screw passes through the metal support component (3) and is fixed in a screw hole provided on the adapter plate (2). A gasket (4) is provided at the screw hole. The gasket (4) is used to adjust the pitch and rotation posture of the corresponding metal mirror (1) by adjusting its own thickness.

2. The high-precision and high-stability hollow corner mirror according to claim 1, characterized in that: The depth of the screw hole is less than 1 / 2 of the thickness of the adapter plate (2) where it is located, and stress relief grooves are arranged on the inner circumferences of the screw hole and the connection hole (5).

3. The high-precision and high-stability hollow corner mirror according to claim 2, characterized in that: The material of the adapter plate (2) is consistent with that of the metal mirror (1).

4. A high-precision and high-stability hollow corner mirror according to any one of claims 1 to 3, characterized in that: Two side edges of each of the metal mirrors (1) are in contact with the front sides or side edges of the other two metal mirrors (1).

5. A method for preparing the high-precision and high-stability hollow corner mirror according to claim 1, characterized in that: The steps include: Step 1: According to the design specifications, three metal mirrors (1) and three adapter plates (2) respectively matching the back surfaces of the three metal mirrors (1) are manufactured, and a plurality of connection holes (5) and a plurality of screw holes are provided on each adapter plate (2); Step 2, bonding the back side of each metal mirror (1) to an adapter plate (2) by means of an adhesive, and fixing them by means of three first screws; Step 3, using integrated manufacturing technology to prepare the metal support component (3), ensuring that its structure is compatible with the main structure of the hollow corner mirror; Step 4: Connect each adapter plate (2) to the metal support assembly (3) through a plurality of second screws, and place a gasket (4) at the screw hole position to obtain a hollow corner mirror preform; Step 5, adjusting the pitch and rotational positions of each metal mirror (1) by trimming the thickness of the gasket (4), thereby adjusting the light beam emission parallel angle accuracy of the hollow corner mirror preform; Step 6, detect the stress deformation of each metal mirror (1) and the corresponding adapter plate (2), and determine whether the metal mirror (1) and the corresponding adapter plate (2) have deformation exceeding the allowable tolerance. If not, the preparation of the high-precision and high-stability hollow corner mirror is completed; if so, return to step 5 until the deformation does not exceed the allowable tolerance, and the preparation of the high-precision and high-stability hollow corner mirror is completed.

6. The method for preparing a high-precision and high-stability hollow corner mirror according to claim 5, characterized in that: The step 1 is specifically as follows: Step 1.1, according to the design specifications, three metal mirrors (1) are manufactured, the size and shape of each metal mirror (1) must meet the requirements of the inverted triangular pyramid structure, and ensure that its side can be in close contact with the front or side of the other two metal mirrors (1); Step 1.2, select a material consistent with the material of the metal mirror (1) to manufacture three adapter plates (2) that match the backs of the three metal mirrors (1) respectively, and set a plurality of connection holes (5) and a plurality of screw holes on each adapter plate (2), and the depth of the screw hole should be less than 1 / 2 of the thickness of the adapter plate (2).

7. The method for preparing a high-precision and high-stability hollow corner mirror according to claim 5, characterized in that: In step 6, the stress deformation of each metal mirror (1) and the corresponding adapter plate (2) is specifically detected as follows: Step 6.1, visually inspect the surfaces of the metal mirror (1) and the corresponding adapter plate (2) to see if there are obvious deformations or cracks, and touch the connection between the metal mirror (1) and the corresponding adapter plate (2) to see if there are any unevenness or looseness; Step 6.2, using a high-precision level or laser level to check the surface flatness of the metal mirror (1) to ensure that it is within the allowable tolerance range; Step 6.3, using a laser interferometer to perform an interference test on the surface of the metal mirror (1) to detect whether there is a slight deformation on the surface; directing a parallel light beam to the metal mirror (1), and determining whether there is stress deformation on the metal mirror by detecting the parallelism of the reflected light beam; Step 6.4, placing the hollow corner mirror in a constant temperature box, performing a temperature cycle test within a certain range, and using a stress analyzer to detect the deformation of the metal mirror (1) and the corresponding adapter plate (2) at different temperatures to ensure that stress deformation exceeding the tolerance is not caused during the temperature change process; Step 6.5: Adjust the pitch and rotation position of the metal mirror (1) by trimming the gasket (4), and perform the precision test of the light beam emission parallel angle again to ensure that the adjusted metal mirror (1) meets the design requirements. Step 6.6: Comprehensively analyze all test data to ensure that the stress and deformation in all test steps are within the allowable range.

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