Research And Development Of The Reaming Processing Technology Based On Deep Hole Boring Machine

As we all know, the deep hole processing is a higher difficult process technology inmachinery industry. It always takes this way“first drilling, next expanding, finallyfashioning”. As for reaming, the traditional reaming is limited to equal diameter hole andstepped hole which is big at the ends and small in the middle. At present, the technologyconcerned this problems has relatively matured. For the“bellied”deep hole with a big middleand both small ends, when the length-diameter ratio is small, central reaming allowance is notbig and machining precision is not high, it can be solved by repeated honing, adjusting the tailtool carrier structure on lathe or using special tooling to make boring bar do eccentricmovement. But when the length-diameter ratio is more than 20, central reaming allowancebecomes larger and machining precision becomes higher, specially the big hole in the middlehas complex alien surfaces, such as cylndrical, conical surface, spherical surface, the currentapproach can not guarantee the manufacturing quantity well because of the great cantilever,poor rigidity, serious cutter relieving and strong vibration.The traditional deep hole boring machine has not the radial mobile turret. In the market,some cutting tools suit for big and short hole, have not functions of self-regulatory orientationand the mandatory scraps discharge; Some cutting tools have small reaming allowance, can’tstretch automatically; Other cutting tools can’t achieve curved surface processing. So far, inthe field of mechanical process manufacturing, there are not processing technology that cansolve this problems and relevant inner reaming cutters at home and abroad.For this problem, it has been using electrochemical machining, but the electrochemicalmachining is limited to use gradually due to the high cost, low efficiency, seriousenvironmental pollution and not producing in large quantities. So in order to meet the demand that this production can be mass produced, combining with the horizontal research projects:AVIC XI’AN AIRCRAFT INDUSTRY COMPANY Z2830 deep hole machine tool’sreconstructive requirement, this paper makes a further research on“bottleneck”problems ininner reaming processing.First, this paper analyses the deep hole boring machine’s process characteristics, machinetool’s movement way, cooling and discharging turnings. Then we are clear to solve this kindof problem what improvement need to do on machine movement’s function and whatinnovation breakthrough need to do on cutting tool structure.Second, since such inner deep-hole reaming allowance is large, the hole is long andlongitudinal feed can’t finished once, this paper puts forward a effective segmented and tieredprocessing principle in the technology. Compared the advantages and disadvantages ofsegmented and tiered push boring, segmented and tiered pull boring, segmented and tieredpush-pull boring, the paper finally chose the segmented and tiered pull boring’s technicalsolutions from precision processing of such super-deep hole. This paper also makes someoptimization on tool path.Third, aiming at the cutter functional requirements in the process of the deep hole andblind deep hole, how to solve cooling and discharging turnings problem as much as possibleunder guaranteeing the cutter’s rigidity, the paper designs different inner reaming boringcutters. This paper expounds the rationality and feasibility of developing this cutter with thefunction of self-directed function, damping and radial self-regulatory device from cutter’sstructure, assembly and design principle.Finally, by using of the finite element analysis software ANSYS, this paper makes staticsand dynamics analysis to the whole cutter, checks the strength and rigidity of the cutter. Thepaper studies the deformation and stress of the front chip removal boring cutter underdifferent segment length, cutting parameters and blade angle. Around the boring cutter’sdeformation and rigidity in the use of different conditions, we can use three methods:①Reasonable decorating self-directed equipment, determining the best segment length.②According to the characteristics of roughing and final machining, selecting the appropriate cutting parameters.③Flexible replacement blades, by changing the blade’s geometry angle,guaranteeing the processing quality. This article compares the deformation and stress of theinternal chip removal boring cutter under push boring and pull boring, verifies the superiorityof pull boring theoretically. At the same time studying of the boring cutter’s dynamiccharacteristics, the paper obtained the natural frequencies, model patterns and frequencyresponse curve. The results of these studies provide a sufficient theoretical basis for how toproperly use such boring cutters to achieve the precision machining of small vibration.