Now we can easily find almost all military weapons systems equipped with various pieces of photoelectric sensors, photoelectric sensors in these cases are more or less used a variety of styles of optical components.
A survey from the U.S. Army report by the material, we know that from 1980 to 1990 the U.S. military laser and infrared thermal imaging products, various optical components needed to have 1,147,700, of which spherical optical parts for the 635 900 non- spherical optical parts for the 234 600, optical parts for the 181 000 plane, polyhedron scanning mirror for the 96200. Take M1 tank, for example, its about using a 90 lens, 30 prism and a variety of mirrors, windows and laser components. Another example is a small AN/AVS-6 pilot used night vision glasses nine aspheric optical parts and the two spherical optical parts.
From the 70's, with infrared thermal imaging and high-energy laser optics, represented by the rapid development of the military. Military optical systems not only requires good image quality, and require small size, light weight, simple structure. This optical processing industry is a severe test. In order to keep up with the pace of development, design and production of Chu fine texture of the optical imaging system, Optical components processing Xingye 70s conducted large-scale technological revolution and innovation, research and development of many new optical parts processing methods such as non-spherical processing method of optical components. Over the past 10 years, new processing technology of optical components further to promote and popularize. At present, foreign countries is more common optical components used in processing technology are:
CNC single point diamond turning techniques, optical glass lens molding technology, optical plastic molding technology, computer numerical control grinding and polishing, epoxy replication, electroforming technologies ... ... and the traditional grinding and polishing techniques. 1. CNC single point diamond turning technology CNC single point diamond turning technology and national defense scientific research institutions from the United States pioneered the development of the 60's, 80's to promote the use of aspheric optical components processing technology. It is ultra-precision CNC lathe, using natural single crystal diamond cutting tools, machine tools and processing environment in the precise control of conditions, the direct use of single point diamond turning tools that meet the optical quality requirements of non-spherical optical components. The technology for processing small and medium size, medium volume of infrared optical materials, crystals and metal parts, characterized by high efficiency, high machining accuracy, good repeatability, suitable for mass production, processing costs than traditional processing technology significantly. Processed using the diamond turning diameter of 120mm out of the following optical components, surface accuracy up to l / 2 ~ 1l, RMS surface roughness value of 0.02 ~ 0.06mm.
At present, the use of diamond turning technology processing materials are: metals, germanium, plastics, infrared optical crystal (mercury cadmium telluride, cadmium antimony, silicon, zinc sulphide, zinc selenide, sodium chloride, potassium chloride, chlorinated strontium, magnesium fluoride, calcium fluoride, lithium niobate, KDK crystal) radio nickel, beryllium copper, germanium-based chalcogenide glass compounds. The material can directly reach the optical surface quality requirements. This technology can also be processed glass, titanium, tungsten and other materials, but has not directly achieve optical surface quality requirements, need to enter a polishing.
CNC single point diamond turning technology can be used in addition to the direct processing of spherical, aspheric optical components, but also can be used to process a variety of optical components and optical mold body parts, such as processing of glass molding dies, copy mold, plastic optical molds and injection molding process used to copy the body of epoxy resin and other optical components. The technology and the combination of ion beam polishing, can be processed high-precision aspheric optical parts; and hard carbon coating and epoxy replication technique combined to produce cheaper precision aspheric mirrors and lenses. If the increase in diamond lathe grinding attachment or ceramic cutting tools, fixture installation and use of precision temperature at -100 ℃ for diamond cutting and other measures, the application of this technology will be further expanded.
Currently, the U.S. University of Arizona optical centers have been using the technology to replace the traditional manual processing, but processing of glass optical components, also can not directly meet the quality requirements grinding into optical mirror, still need to be flexible polishing. Single point diamond turning of optical components technical and economic effect is very obvious, such as processing a diameter of 100mm, 90 ° off-axis parabolic mirror, if the traditional method of grinding and polishing processes processing, surface accuracy of up to 3mm (5l), processing time takes about 12 On each processing costs of the parabolic mirror 5 million. The use of diamond turning method, three weeks can be completed, the processing cost only 0.4 million, surface accuracy up to 0.6μm (1λ). Honeywell will use this technology Infrared detection device processing AN/AAD-5 4 sided scanning rotating mirror. Polygon size of each side of 88.9 '203 .2 mm, the flatness of each surface requirements for l / 2, angle accuracy of 90 ° ± 42. Using a lathe, 15 months on the processing of the 124 scanning rotating mirror, the quality of design requirements are met. Each rotating mirror than the traditional method of processing the processing cost savings 2770 U.S. dollars. Honeywell produced by this process 200 4 sided rotating mirror, for a total savings of about 900,000 U.S. dollars. But also for the AN/AAD-5 infrared detection devices processed 100,000 flat mirror, cost-saving one more than 10 million U.S. dollars. In 1980 the 10 years between 1990, the plane (50'50mm), polyhedron (diameter 90mm), spherical (diameter 100mm), non-spherical (diameter 125mm) optical components such as four kinds of military processing costs, according to a conservative calculation of the economic effects of U.S. Department of Defense total savings of approximately 400 million U.S. dollars.
Diamond turning machine is the key technology of diamond turning process, no diamond turning machine, it is impossible to achieve diamond turning of optical components of new technology. Diamond turning machine is a high precision machine tools, machine tool spindle accuracy and precision sliding board exercise machine to be higher than the average several orders of magnitude, spindle bearings and sliding board rail usually static air bearings and hydraulic supporting structure, moving parts of machine tools the relative position determination using laser displacement measurement device. In the whole process of workpiece, using laser interferometer measurement of the workpiece surface error. Lathe equipped with a feedback device, can compensate for motion errors. Diamond turning machine is a major manufacturer of precision machine tools the United States, Moore Precision Inc. Company and Pu Naimo. Into the 90's, the Japanese Toshiba Machine Company began producing the lathe. Moore precision machine tool manufacture and sell the main product is Moore M-18, -40 aspheric processing machine, Moore T-type machine tool bed, Moore optical surface processing machine, Moore M-18 You Lin aspheric processing machines. Pu Naimo precision manufactured products sold mainly MSG-325 type, ASG-2500 type, Nanoform600 type, Ultra 2000 and other diamond-type lathe. Toshiba Machine to sell company products ULG-100A (H) diamond turning machine.
Diamond turning machine prices are very high, but rising. To MSG325 lathe, for example, each value in the early 80s to 30 to 40 million, and to the early 90's price has increased to nearly every one million U.S. dollars. The price for users is a big financial burden, promote the universal application of a certain degree of difficulty. Therefore, the current low-cost countries are actively developing the diamond turning machine. Here are some currently promote the use of diamond turning machine.
(1) Moore M-18 machine non-spherical
Mohr M-18 machine is a non-spherical 3-axis CNC ultra-precision machining systems, you can use a single point diamond turning tool, you can use the wheel grinding, not only all kinds of high precision surface processing, spherical and aspherical optics parts, but also processing the mold surface and other surfaces. Diamond grinding wheels turning and the combination of expanded processing capacity machine. For example, precision mold processing, such as in a diamond turning process can be completed. First use of abrasive wheels in the mold substrate processed the same surface shape tolerances, then coated electroless nickel, the final single point diamond cutting tool, turning the surface of electroless Nickel to complete the finishing mold. The machines use the Allen-Bradley7320 type, 8200 type or the General Electric Company 2000 of the computer numerical control system, position control lathes used Newlett-Packard5501A laser sensor system. Moore M-18 machine main technical performance indicators are as follows: X axis travel 410mm; Z axis travel 230mm; air bearing spindle center to table a distance of 292mm, the distance to the rotating work table is 178mm; X-axis and Z axis All trips on the line of the 0.5mm; X-axis and Z-axis vertical in the entire journey on the degree of 1μrad; X-axis Z-axis in the entire journey on the deflection angle for the 0.5μrads; X-axis Z-axis positioning accuracy on the whole trip 1.5mm; X-axis and Z-axis positioning accuracy per 25.4mm stroke is 0.5mm; B axis 360 ° when the angle deviation of ± 3μrads; X-axis and Z axis reading accuracy of 5mm; B-axis reading accuracy of 1.3 μrads; spindle axis error of 0.05mm, the radial error 0.2mrad; Machine Dimensions (H 'length' width) for 1778'2032'1800mm.
(2) Pu Naimo MSG-325 diamond turning
Pu Naimo MSG-325 diamond-type lathe is a dual-axis diamond turning machine CNC. 6t machine using a heavy granite base, granite base installed in the air pads for vibration isolation, the vibration is reduced to 2Hz. X and Z slide plates are installed in the granite base, two mutually perpendicular sliding plate installed in the entire trip on the vertical accuracy is within 0.76mm. X slide board with an interchangeable turret, Z slide board with an air bearing spindle. 2 Slide in The exact location determination using a laser sensor system, accuracy of 0.025mm. The machine can process the application of infrared and visible light of various spherical and aspherical lenses, Fresnel lenses, mirrors, mirror axis conic section, polyhedron mirrors and video cameras and other precision optical components. Processing in optical components, laser interferometer can be used on the processing conditions for non-contact measurement of surface shape. The main technical performance indicators of machine are as follows: the machine spindle air bearing, in 1000 turn / min, measured at the front end, the radial and axial runout are 0.1mm; drive motor for the 1/3HP100 ~ 2400 turn / min DC was waiting service motor; using air bearing the name of X-Slide in size 609'762mm, the maximum stroke is 304mm, the maximum speed 20cm/min, horizontal motion error 0.5mm, vertical movement error of 1.27mm, precision screw driver Motor 1HP0 ~ 2500 turn / min; Z stroke is the largest Slide 203mm, other performance indicators are the same with the X slide plate; workpiece diameter, the normal machine tool structure for 356mm, machine tool structure for large aperture 560mm; workpiece Max depth of 204mm; workpiece diameter 150mm, the workpiece surface accuracy up to l / 2.
(3) ULG-100A (H)-based ultra-precision aspheric diamond turning machine
This machine is the Toshiba Machine Company 90 products starting from June 1992, the monthly production of 2 sets, each priced at 50 million yen machine. High rigidity spindle static ultra-precision air bearings, machine tool numerical control device with feedback function. It can process a variety of optical components and non-spherical lens molding metal mold. Precision up to 0.01mm. Molding metal mold used for diamond tools and grinding wheels turning and grinding, can achieve mirror surface quality. The main technical performance indicators of machine are as follows: X-axis machine tool (grinding wheel) Maximum stroke is 150mm; Z axis (workpiece axis) maximum stroke is 100mm; grinding wheel maximum speed of 40,000 turn / min; grinding wheel motor 1kW/40000 switch / min; workpiece spindle speed 20 ~ 1,500 rpm / min; workpiece spindle motor 0.25kW/3000 transferred / min; Grinding wheel spindle axial and radial runout 0.05mm; workpiece spindle axial and radial runout 0.05mm; X axis linear of 0.1mm/150mm; Z axis linear 0.1mm/100mm.
