A light and small lens anti-mass level impact design method

Abstract

The application discloses a light and small lens anti-large impact design method, which comprises the following steps: a lens group in a main bearing lens barrel is divided into multiple sections, and a pressing ring is used to press and fix the lens group; the main bearing lens barrel is provided with glue injection holes in the area of each section of the lens group, optical glue is injected to the non-working surface of the optical lens part through the glue injection holes; and glue flow grooves are arranged around the inner wall of the cylinder of the main bearing lens barrel which is matched with each section of the lens group, the glue flow grooves are communicated with the glue injection holes, and the optical lens part is stable and firm in the main bearing lens barrel. In the centering processing of the optical lens part, stress-free assembly is realized. Through the system engineering idea of "strengthening, buffering and protecting", the application overcomes the problems that the lens is broken and the optical axis is deviated due to the lens delamination, displacement or loosening of the lens under the extreme physical environment, and guarantees the reliability and imaging quality of the core optical system under the extreme physical environment.

Description

Technical Field

[0001] This invention relates to a design method for lightweight lenses to withstand large-scale impacts, belonging to the field of weapon optical systems to withstand large-scale impacts. Background Technology

[0002] Star sensors are used in spacecraft, and the lens, as a core component within the product, must maintain stable optical performance, structural integrity, optical axis stability, and clear imaging when subjected to massive impacts (such as explosions, drops, and severe vibrations). Ensuring the integrity of the optical lens structure and imaging stability is crucial. Faced with extremely harsh operating environments, the internal lens elements of ordinary conventional lenses are highly susceptible to deformation due to compression or stretching, leading to reduced optical performance or even failure.

[0003] High-precision, lightweight lenses are mainly composed of several lens groups. Their impact resistance is mainly related to the strength of structural materials, anti-loosening measures, and stress-free centering and adjustment methods. Under the same mechanical impact conditions, deformation caused by compression or tension between the lens and the structure can lead to a decrease in the performance of the optical system or even failure. Increasing the amount of adhesive applied can reduce the risk of collision damage to optical and mechanical parts, but this measure will increase the centering and assembly stress and make it more difficult to control the surface shape of the lens during the centering process, so the effect is not ideal.

[0004] Therefore, in the actual design of lenses, a complex trade-off must be made between shock resistance, optical performance, weight, size, cost, and manufacturability. While ensuring the lens is small and lightweight, the core objective of lens shock resistance technology is to set up barriers in the path of impact energy transmission, and to maximize the protection of the structural stability of precision optical components through energy absorption, dissipation, and structural reinforcement. Summary of the Invention

[0005] The technical problem solved by this invention is to overcome the shortcomings of the prior art and propose a lightweight lens design method to resist large-scale impacts. Through the design of precise force control by segmented clamping, anti-loosening buffer of adhesive layer and stress-free centering assembly, the negative risks such as lens deformation and breakage under large-scale impact conditions are solved.

[0006] The technical solution of this invention is: A method for designing lightweight lenses to withstand large-scale impacts, comprising: The mirror assembly inside the main load-bearing mirror tube is divided into multiple sections, and pressure rings are used to press and fix the mirror assembly sections. The main load-bearing lens barrel has glue injection holes in the area where each lens group is located; when the optical lens parts are put into the frame, optical glue is applied to the non-working surface of the optical lens parts through the glue injection holes; during the centering process of the optical lens parts, the surface RMS value of the optical lens parts is measured to enable the optical lens parts to achieve stress-free assembly. A glue-flowing groove is provided around the inner wall of the cylinder that mates with each lens assembly in the main load-bearing lens barrel. The glue-flowing groove is connected to the glue injection hole, so that the optical lens parts are stable and firm inside the main load-bearing lens barrel.

[0007] Furthermore, the main load-bearing lens barrel is made of titanium alloy.

[0008] Furthermore, during the centering process of optical lens parts, the surface RMS value of the optical lens parts is measured using an interferometer. The surface RMS value should be better than 1 / 20λ, where λ is the wavelength.

[0009] Furthermore, based on the differences in lens diameter, the lens group is divided into several corresponding segments.

[0010] Furthermore, each lens assembly is equipped with a pressure ring with threads. The main load-bearing lens barrel is securely connected to the pressure ring through the threaded connection, and the lens assembly is pressed and fixed.

[0011] Furthermore, when the optical lens parts are placed into the frame, optical adhesive is applied to the non-working surface of the lens circumference through the adhesive injection hole. The optical adhesive grade is XM-31.

[0012] Furthermore, the centering frame is made of titanium alloy.

[0013] Furthermore, the main load-bearing lens barrel has multiple glue injection holes in the area where each lens assembly is located. Each glue injection hole is connected to the glue flow groove, so that the glue injection amount is consistent and a buffer and adhesive layer is formed between the main load-bearing lens barrel and each optical lens component.

[0014] The advantages of existing technologies are: (1) Compared with traditional lightweight lens designs, this invention adopts a segmented clamping and fixing method with front and rear clamping rings. The two lens groups are divided into two sections and clamped and fixed segment by segment, which improves the uniformity of force and fit during clamping. This solves the problems of difficulty or poor effect of one-time overall clamping, which may lead to lens group deformation or excessive stress and other uncontrollable factors. It also avoids the problem of insufficient pre-tightening force of the clamping rings under large-scale high-intensity impacts. At the same time, the impact energy first acts on the main load-bearing lens barrel, and is then absorbed, buffered and converted into heat energy dissipation by the segmented clamping rings, which significantly reduces the peak impact force transmitted to the core component of each clamping ring. The clamping rings are grouped according to the lens structure, so that the lens volume is not too large, thus avoiding the contradiction that the goal of small size and lightweight design cannot be achieved at the same time.

[0015] (2) Compared with traditional lightweight lens designs, this invention selects titanium alloy as the main load-bearing lens barrel and centering lens frame for structural material selection. It has a high degree of matching with the linear expansion coefficient of glass material. Under the premise of pursuing lightweight and miniaturized design, this material has high specific stiffness, is lightweight and high-strength, corrosion-resistant and temperature-resistant, and its strength and stiffness are sufficient to withstand large-scale high-frequency impacts of 8000g and above in the external environment. On the one hand, it ensures that the strength of the main lens barrel structure itself will not be damaged by the harsh external environment, and on the other hand, it ensures sufficient stiffness to ensure that the optical components in the main lens barrel will not be squeezed or stretched and deformed, which would lead to a reduction in the performance of the optical system or even failure.

[0016] (3) Compared to traditional lightweight lens designs, this invention employs a cylindrical inner wall with a wider arc-shaped glue-flow groove around the glue-filling hole of the main load-bearing lens barrel and each optical component, which is connected to the glue-filling hole. This ensures good glue filling after the optical system is assembled and adjusted, and that the glue amount at each injection point is consistent. This guarantees sufficient buffering and adhesive layer between the main lens barrel and each optical component, making the optical components stable and firm inside the main lens barrel. This ensures the reliability of the glue-filling process, the uniformity of the glue distribution, and the final quality stability of the lens. It also has good buffering and anti-loosening capabilities when subjected to strong external impacts, reducing the risk of damage to optical and mechanical parts and avoiding damage from rapid impacts. Attached Figure Description

[0017] Various other advantages and benefits will become apparent to those skilled in the art upon reading the following detailed description of preferred embodiments. The accompanying drawings are for illustrative purposes only and are not intended to limit the invention. Furthermore, the same reference numerals denote the same parts throughout the drawings. In the drawings: Figure 1 This is a schematic diagram of a single lens assembly structure according to an embodiment of the present invention; Figure 2 This is a schematic diagram showing the position of the optical adhesive applied to the non-working surface of the lens circumference according to an embodiment of the present invention; Figure 3 This is an example of an impact response spectrum curve from an embodiment of the present invention. Figure 4 This is a diagram of the lens outline according to an embodiment of the present invention. Detailed Implementation

[0018] Exemplary embodiments of the present disclosure will now be described in more detail with reference to the accompanying drawings. While exemplary embodiments of the present disclosure are shown in the drawings, it should be understood that the present disclosure may be implemented in various forms and should not be limited to the embodiments set forth herein. Rather, these embodiments are provided so that this disclosure will be thorough and complete, and will fully convey the scope of the disclosure to those skilled in the art.

[0019] This invention proposes a design method for lightweight lenses to withstand large-scale impacts. Through a systems engineering approach of "strengthening → buffering → protection", it comprehensively utilizes materials science, precision mechanical design and dynamic principles to progressively reduce the impact energy in the energy transmission chain. This overcomes the problems of lens breakage and optical axis drift caused by internal lens delamination, displacement or loosening under extreme physical impact conditions, ultimately ensuring the reliability and imaging quality of the core optical system under extreme physical conditions.

[0020] This design methodology specifically includes: S1: Strengthen the lens structure The lens employs a segmented clamping and fixing method to solve the problems of uneven stress and mismatched coefficients of thermal expansion. The lens assembly is divided into two sections based on the difference in lens diameter, such as... Figure 1 , Figure 4 As shown, the lens barrel and the pressure ring are connected in a stable manner by the front group of M39×0.5 fine thread large pressure ring 1 and the rear group of M31×0.5 fine thread small pressure ring 3 in a segmented thread pattern, and the lens assembly is pressed and fixed. This improves the uniformity of force and fit during pressing, solves the problem of difficulty or poor effect of one-time overall pressing, which may lead to uncontrollable factors such as lens assembly deformation or excessive stress, and avoids the problem of insufficient preload of pressure ring under a large number of high-intensity impacts.

[0021] S2: Buffering treatment for lens materials In terms of structural material selection, titanium alloy is chosen because of its advantages such as light weight, high strength, corrosion resistance, and temperature resistance. It also has a high degree of matching with the linear expansion coefficient of glass. Titanium alloy is selected as the material for the main load-bearing lens barrel 2 and the centering lens frame 6. Under the premise of pursuing lightweight and miniaturized design, this material has a high specific stiffness, and its strength and stiffness are sufficient to withstand a large number of high-frequency impacts of 8000g or more from the external environment. On the one hand, it ensures that the structural strength of the main load-bearing lens barrel 2 will not be damaged by the harsh external environment. On the other hand, it ensures sufficient stiffness to ensure that the optical components inside the main load-bearing lens barrel 2 will not be deformed by compression or tension, which would lead to a decrease in the performance of the optical system or even failure.

[0022] S3: Perform buffering. Optical lens components are assembled and adjusted using a centering process. When fitting the lens into the frame, XM-31 optical adhesive 5 is applied to the non-working surface of the lens circumference. Figure 2 As shown, during the mounting and alignment of optical components, the RMS value of the optical lens surface profile is measured using a Zygo interferometer and is better than 1 / 20λ, ensuring stress-free assembly of the optical components after final product assembly. Thus, in the event of severe vibration or impact, the XM-31 adhesive acts as a buffer against collisions between the lens and the mechanical structure, thereby reducing the risk of damage to the optomechanical components.

[0023] S4: Perform protective treatment The main load-bearing lens barrel 2 has six evenly distributed injection holes around the circumference at the location of each lens assembly for applying XM-31 optical adhesive. At the same time, the main load-bearing lens barrel 2 has a 3.5mm wide arc-shaped adhesive flow groove 4 around the inner wall of the cylinder that mates with each lens assembly, which is connected to the injection holes. This ensures good adhesive filling after the optical system is assembled and adjusted, and that the amount of adhesive applied to each injection point is consistent. This ensures that there is sufficient buffer and adhesive layer between the main load-bearing lens barrel 2 and each optical component, making the optical components stable and firm inside the main load-bearing lens barrel 2. It also has good buffering and anti-loosening capabilities when subjected to strong external impacts, reducing the risk of damage to optical and mechanical parts and avoiding damage from rapid impacts.

[0024] The lens manufactured using the design method of this invention has a working spectral range of 450-800nm, a system F / # of 1.5, a diagonal field of view of 18°, and can achieve a dispersion spot diameter of less than 15μm with 80% energy concentration at infinity. The lens weighs only 230g, and compared to ordinary lenses, it exhibits significantly superior shock resistance. The shock response spectrum curve is shown below. Figure 3 As shown, the shock response spectrum (SRS) describes the relationship between the peak acceleration response (unit: g) of a single-degree-of-freedom system under shock and the system's natural frequency.

[0025] This invention features low cost, low price, small size, and light weight. Optical lenses must simultaneously possess lightweight yet high strength, low residual stress, and minimal optical axis misalignment under heavy impact. Through precise force control via segmented clamping, anti-loosening adhesive layer buffering, and stress-free centering assembly, these measures are key elements for achieving a lightweight, compact lens capable of withstanding heavy impacts under complex conditions, sufficient to withstand high-frequency impacts of 8000g or more from external environments. Under the same external dimensions, compared to traditional optical lens designs, this invention is more conducive to stress release and optical performance stability of optical components, eliminating the negative risks of lens deformation and breakage under heavy impact. The design is safer, more reliable, more stable, and has greater design margins, meeting usage requirements and possessing a certain degree of versatility and practicality.

[0026] The embodiments described above are merely preferred embodiments of the present invention. Ordinary variations and substitutions made by those skilled in the art within the scope of the technical solution of the present invention should be included within the protection scope of the present invention.

Claims

1. A design method for lightweight lenses to withstand large-scale impacts, characterized in that, include: The mirror assembly inside the main load-bearing mirror tube is divided into multiple sections, and pressure rings are used to press and fix the mirror assembly sections. The main load-bearing lens barrel has glue injection holes in the area where each lens assembly is located; When the optical lens parts are placed into the frame, optical adhesive is applied to the non-working surface of the optical lens parts through the glue injection hole; during the centering process of the optical lens parts, the RMS value of the surface of the optical lens parts is measured to enable stress-free assembly of the optical lens parts. A glue-flowing groove is provided around the inner wall of the cylinder that mates with each lens assembly in the main load-bearing lens barrel. The glue-flowing groove is connected to the glue injection hole, so that the optical lens parts are stable and firm inside the main load-bearing lens barrel.

2. The lightweight lens design method for resisting large-scale impacts according to claim 1, characterized in that, The main load-bearing lens barrel is made of titanium alloy.

3. The lightweight lens design method for resisting large-scale impacts according to claim 1, characterized in that, During the centering process of optical lens parts, the RMS value of the surface profile of the optical lens parts is measured using an interferometer. The RMS value of the surface profile should be better than 1 / 20λ, where λ is the wavelength.

4. The lightweight lens design method for resisting large-scale impacts according to claim 1, characterized in that, Based on the differences in lens diameter, the lens group is divided into several corresponding sections.

5. The lightweight lens design method for resisting large-scale impacts according to claim 1, characterized in that, Each lens assembly is equipped with a pressure ring with threads. The main load-bearing lens barrel is securely connected to the pressure ring through the threaded connection, and the lens assembly is pressed and fixed.

6. The lightweight lens design method for resisting large-scale impacts according to claim 1, characterized in that, When optical lens parts are placed into the frame, optical adhesive is applied to the non-working surface of the lens circumference through the adhesive injection hole. The optical adhesive grade is XM-31.

7. The lightweight lens design method for resisting large-scale impacts according to claim 1, characterized in that, The centering frame is made of titanium alloy.

8. The lightweight lens design method for resisting large-scale impacts according to claim 1, characterized in that, The main load-bearing lens barrel has multiple glue injection holes in the area where each lens assembly is located. Each glue injection hole is connected to the glue flow groove, so that the glue injection amount is consistent and a buffer and adhesive layer is formed between the main load-bearing lens barrel and each optical lens component.

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