High speed milling machines a machine tool

The component propping up such as the lathe bed of machine tool of cutting of high speed of the component that prop up should have the machine tool of tall stability to be moved very well, static stiffness, heat up stiffness and first-rate damp character. Major machine tool uses high quality, tall tigidity and Gao Kang piece sexual casting pig regards the component that prop up as material, some machine tool companies still add the polymer concrete of tall damp character in base, fight in order to increase its brace up gender and thermal stability, this not only can make sure machine tool precision is stable, the cutting tool when also can preventing cutting brace up quiver. Use enclosed lathe bed design, whole casts lathe bed, structure of symmetrical lathe bed deserves to densely covered reinforcement waits also is the important step that increases machine tool stability. The branch of research and development of company of a few machine tools is in design process, still use mode analysis and finite yuan of structure computation, optimized a structure, make the machine tool component that prop up more stable and reliable. 2.

The main shaft function of machine tool of high speed of machine tool main shaft is the fundamental condition that realizes treatment of high speed cutting. The rotate speed limits of main shaft of machine tool of high speed cutting is 10000"100000m/min, main shaft power is more than 15kW. Through main shaft compresses air or cooling the system controls the axial clearance between knife handle and main shaft to be more than 0.

005mm. Still ask main shaft is had rise quickly fast, the function that showing emplacement allows to stop quickly (have extremely tall horn to add decelerate to spend) namely, because main shaft of this high speed often uses a liquid static pressure bearing type, air is static press nitrogen of bearing type, hot pressing to change silicon (Si3N4) the configuration such as type of bearing of in suspension of magnetism of bearing of pottery and porcelain. Lubricate to use oil gas more eject is lubricant, lubricant wait for a technology. Main shaft refrigeration uses water-cooling of main shaft interior or air cooling commonly. 3.

System of machine tool drive is the need that contented mould high speed machines, high speed machines the drive system of the machine tool to should have following character: (The feed rate with high 1) . Consider to make clear, to small diameter cutting tool, raise rotate speed and every tine feed to be helpful for reducing cutting tool to wear away. At present commonly used feed speed limits is 20"30m/min, if use transmission of guide screw of big lead ball, feed speed can amount to 60m/min; Use linear electric machinery to be able to make feed speed achieves 120m/min. (The acceleration with tall 2) . To the high speed of profile of three-dimensional and complex curved surface treatment asks drive system has good acceleration character, the driver that asks to offer high speed feed (speed speed makes an appointment with 40m/min, 3D outline machines speed to be 10m/min) , can offer 0.

4m/s2 is spent to the acceleration of 10m/s2 and decelerate. Machine tool manufacturer uses guide screw of the ball guide screw of small lead of pilot of servo of position of complete closed circuit, large size, high quality or big lead bull mostly. As the development of electric machinery technology, advanced linear motor has come out, apply successfully at CNC machine tool. Advanced linear electromotor drive makes CNC machine tool has quality no longer the problem such as inertial, lead, lag and vibration, accelerated servo to answer speed, raised servo to control precision and precision of machine tool treatment. 4.

The numerical control system with numerical control advanced system is to make sure the pattern is mixed the crucial factor of quality of treatment of curved surface high speed and efficiency, cutting of mould high speed machines logarithm to accuse main demand of the system to be: (1) high-speed number dominates return circuit (Digital Control Loop) , include: 32 or 64 collateral processor and 1.

The hard disk of 5Gb above; Cutty is linear time of electric machinery sampling. (Of 2) speed and acceleration before make a present of is controlled (Feed Forward Control) ; The crawl of digital drive system is controlled (Jerk Control) . (The interpolation method with advanced 3) (the batten interpolation) that is based on NURBS, in order to obtain good exterior quality, exact size and tall geometrical precision. (4) pretreatment (Look-ahead) function. The requirement has register of high capacity amortize, can be read beforehand and check many block (if DMG machine tool can amount to 500 block, simens system can amount to 1000"2000 block) , so that be being machined exterior figure (curvature) when producing change can adopt the measure such as change feed speed in time to wait with avoiding to cut. (5) error compensates a function, the hot error compensation that because the hair thermal conductivity such as linear electric machinery, main shaft is sent,includes, quadrantal error compensation, measure systematic error compensation to wait for a function. In addition, the demand that treatment of cutting of mould high speed transmits speed to data is very high also. (The data interface of 6) tradition, if RS232 is serial,transmission speed of the mouth is 19.

2kb, and a lot of advanced machining center already all used aether local area network (Ethernet) undertakes data is transmitted, speed can amount to 200kb. 5.

Treatment of cooling and lubricant high speed uses the hard alloy cutting tool that takes coat, fall in the circumstance of high speed, high temperature need not cutting fluid, cutting efficiency is taller. Because,this is: High speed of milling main shaft rotates, if cutting fluid wants to reach cutting area, want to overcome huge to leave mental efforts above all; Although it overcame centrifugal force to enter cutting area, likely also as a result of the high temperature of cutting area evaporate instantly, cooling effect is very little do not have even; At the same time cutting fluid can make the temperature of ministry of cutting tool blade intense change, bring about the generation of crackle easily, should use oil so / the means of dry type cutting with gas lubricant refrigeration. This kind of means can use high-pressured gas to blow the cutting that cutting area produces quickly, walk along many cutting tropics thereby, at the same time the lube of classics pulverization can be in ministry of cutting tool blade and workpiece surface form a paper-thin microcosmic diaphragm, can prolong cutting tool life effectively and improve the exterior quality of the spare parts. CNC Milling