| With the development of Nomex honeycomb core material applications continue to expand,the market demand is more and more big,the quality requirements are increasingly high,the quality of the raw materials of Nomex honeycomb has reached a very high level,it restricts the wide application of this material is required for processing the high.Nomex honeycomb core material is a typical difficult to machine material.The traditional high-speed milling is prone to cause burrs,defects and other phenomena.It is difficult to achieve high-quality and efficient processing.Aiming at these problems,scholars have introduced ultrasonic cutting technology to the field of Nomex honeycomb core machining,but our country started late.At present,the research of ultrasonic milling technology is still in its initial stage.The domestic ultrasonic processing equipment is mainly purchased from foreign countries,but the key technology can not be obtained.Through the design of structural innovation,a sawtooth disc knife with sharp cutting edge is designed to achieve high quality and efficient cutting of Nomex honeycomb core.The main research contents and results are as follows:(1)The performance characteristics of Nomex materials are analyzed and summarized,the innovative design of a sawtooth knife with a sharp cutting edge,a cutting force model of sawtooth knife ultrasonic inspection,the sawtooth knife designed in ultrasonic cutting conditions effectively than ordinary cutting conditions reduce the cutting force.(2)The design of simulation experiment,establish ultrasonic cutting system stability simulation model using SIMULINK module of MATLAB software,through the simulation experiments:spindle speed in 0?1400(r/min)in the range of teeth number is small and stable valve more;in 1400-1800(r/min)in the range of number of teeth more stable more flap.It is found that the removal rate of material is larger when the number of tool teeth is 36.(3)Modal analysis of sawtooth disc knives is carried out.The maximum amplitude of all vibration occurs on the edge of the cutter.The displacement of the twelfth stage vibration cutter is distributed along the radial direction.When transmitted to the edge of the cutter,the amplitude is the largest,the amplitude distribution is regular,and the vibration mode is ideal.In the case of 19.5?20HKz frequency,6 sets of tool structure parameters conforming to the frequency range are discussed and analyzed.(4)The cutting simulation analysis of ultrasonic cutting of Nomex honeycomb core material is carried out.With the tool diameter 45mm to 55mm,the cutting force X,Y and Z direction decrease by 9.1%,7.9%and 6.2%,respectively,and cutting heat is reduced by 8.9%.With the cutting angle of the cutter from 10 to 18 degrees,the cutting force X,Y,and Z increased by 10.2%,11.2%and 11%respectively,and the cutting heat increased by 9.4%.With the cutting angle of 1 to 9 degrees,the cutting force X,Y and Z increased by 7.5%,9.1%and 9.5%respectively,and the cutting heat increased by 7.4%.(5)The optimized saw tooth disc cutter has harmonic response analysis for the saw tooth disc cutter and the horn body,and the amplitude magnification is 6.15?6.16,which is 4%different from the design amplitude multiplier.It is within the error request range.When the shape map is best,the cutting edge of the tool has the largest amplitude,which is in line with the requirements of the ultrasonic vibration cutting technology for the horn and the cutting tool. |
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