The hottest ultra precision machining and ultra hi

2022-09-22
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Ultra precision machining and ultra high speed machining technology

I. technology overview

ultra high speed machining technology refers to a modern machining technology that uses cutting tools of superhard materials to improve the material removal rate, machining accuracy and machining quality by greatly improving the cutting speed and feed speed

the cutting speed range of ultra-high speed machining varies with different workpiece materials and different cutting methods. At present, it is generally recognized that the cutting speed range of ultra-high speed cutting of various materials is: aluminum alloy has exceeded 1600m/min, cast iron is 1500m/min, ultra heat resistant nickel alloy is 300m/min, titanium alloy is 150~1000m/min, and fiber reinforced plastic is 2000~9000m/min. The cutting speed range of various cutting processes is: turning 700~7000m/min, milling 300~6000m/min, drilling 200~1100m/min, grinding more than 250m/s, etc

ultra high speed machining technology mainly includes: ultra-high speed cutting and grinding mechanism research, ultra-high speed spindle unit manufacturing technology, ultra-high speed feed unit manufacturing technology, ultra-high speed machining tool and abrasive tool manufacturing technology, ultra-high speed machining automatic detection and control technology, etc

ultra precision machining currently refers to the machining technology of the machined parts with the dimensional accuracy higher than 0.1 M, the surface roughness Ra less than 0.025 m, and the positioning accuracy of the machine tool with the resolution and repeatability higher than 0.01 temperature sensitive rod: screw in thermocouple m, also known as sub micron machining technology, and is developing to nano machining technology

ultra precision machining technology mainly includes: Research on Mechanism of ultra precision machining, research on equipment manufacturing technology of ultra precision machining, research on ultra precision machining tools and grinding technology, research on ultra precision measurement technology and error compensation technology, and Research on working environment conditions of ultra precision machining

II. Current situation and development trends at home and abroad

1. Ultra high speed machining

the research on ultra high speed machining in industrial developed countries started early and has a high level. In this technology, the leading countries are Germany, Japan, the United States, Italy and so on

in ultra-high speed machining technology, superhard material tools are the premise and prerequisite to realize ultra-high speed machining, ultra-high speed cutting and grinding technology is the process method of modern ultra-high speed machining, and high-speed CNC machine tools and machining centers are the key equipment to realize ultra-high speed machining. At present, tool materials have developed from carbon steel and alloy tool steel, through high-speed steel, cemented carbide steel and ceramic materials, to artificial diamond and polycrystalline diamond (PCD), cubic boron nitride and polycrystalline cubic boron nitride (CBN). The cutting speed has also increased from 12m/min to more than 1200m/min with the innovation of tool materials. In the past, corundum series and silicon carbide series were mainly used as grinding wheel materials. G.E company of the United States first succeeded in diamond synthesis in the 1950s, and CBN was first developed in the 1960s. In the 1990s, CB Hansen, a ceramic or resin binder, suggested that you fill the tension oil box with n grinding wheel and diamond grinding wheel at this time. The linear speed can reach 125m/s, some can reach 150m/s, and the single-layer electroplated CBN grinding wheel can reach 250m/s. Therefore, some people believe that with the continuous development of new tool (abrasive) materials, the cutting speed should be doubled every ten years, and the emergence of subsonic and even supersonic machining will not be too far away

in terms of ultra-high speed cutting technology, in 1976, Vought company of the United States developed an ultra-high speed milling machine with a maximum speed of 20000rpm. What is particularly striking is that the Institute of production engineering and machine tools (PTW) of Darmstadt University of technology in Federal Germany has systematically carried out research on the mechanism of ultra-high speed cutting since 1978, and conducted high-speed cutting tests on various metallic and non-metallic materials. Federal Germany has organized dozens of enterprises and provided more than 20 million marks to support this research work. Since the mid and late 1980s, commercialized ultra-high speed cutting machines have continued to appear, Ultra high speed machine tools have developed from a single ultra-high speed milling machine to ultra-high speed turning milling machine, drilling milling machine and even various high-speed machining centers. Switzerland, Britain and Japan have also launched their own ultra-high speed machine tools. The maximum speed of the spindle of hg400iii machining center of Hitachi precision machine in Japan is 36000~40000 R/min, and the fast moving speed of the workbench is 36~40 M/min. The feed moving speed of hvm800 high-speed machining center of Ingersoll company in the United States, which adopts linear motor, is 60m/min

in terms of high-speed and ultra-high-speed grinding technology, people have developed many high-speed and high-efficiency grinding technologies, such as high-speed and ultra-high-speed grinding, deep creep feed grinding, deep fast feed grinding (HEDG), multi disc grinding wheel and multi wheel frame grinding. These high-speed and high-efficiency grinding technologies have been developed and applied in the past 20 years. German Guehring automation company manufactured the world's first powerful 60kW powerful CBN grinding wheel grinder in 1983, with a vs of 140~160m/s. Ashen University of technology and Bremen University in Germany have achieved internationally recognized high-level achievements in the research of high-efficiency deep grinding, and actively carry out research on High-Efficiency Deep Grinding of difficult to machine materials such as aluminum alloy, titanium alloy and Inconel alloy. Bosch Company of Germany applies CBN grinding wheel for high-speed grinding of gear tooth profile, and uses electroplated CBN grinding wheel for ultra-high-speed grinding to replace the original process of gear hobbing and shaving, and processes the gear tooth profile of 16MnCr5 material, with vs = 155m/s, and its q'reaching 811mm3/mm s. German Kapp wire pipe water drop company applies high-speed deep grinding to process deep grooves of pump parts driven by "replacing steel with plastic". The workpiece material is 100Cr6 bearing steel, and the electroplated CBN grinding wheel is used. The vs reaches 300m/s, and its q` = 140mm3/mm s. During grinding, 10 quenched vane pump rotors can be clamped at one time and the rotor slots can be grinded out at one time. During grinding, the workpiece feed speed is 1.2m/min, and the average processing time of each rotor is only 10 seconds. The slot width accuracy can be guaranteed to be 2 M. a grinding wheel can process 1300 workpieces. At present, the practical grinding speed in Japanese industry has reached 200m/s. In 1996, the grinding research center of the University of Conneticut in the United States, on its centerless cylindrical high-speed grinder, the maximum grinding speed of the grinding wheel reached 250m/s

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