Grinding processes control of medium active measuring instrument and application
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source:MOMEYER CNC Machining
Be being measured actively is to point to in machining process, measuring the size of workpiece from beginning to end by measurement unit, deliver amount of its size variation control appearance at any time, issue signal by control appearance again (if kibble, essence is ground, light is ground, wait for signal to dimension) the action that dominates a machine tool. Because it can make operate personnel to need not stop machine can measure workpiece, reduced labor intensity, improved manufacturing efficiency, reduced percent defective, the work measure consistency that at the same time treatment gives is taller, special suit to be used at be in exercise of big batch automation line, the treatment that is like spare parts of car component, bearing. 1. Of active measuring instrument form basically active measuring instrument is main by appearance of measurement unit, actuating device, control 3 parts are comprised. (1) measurement unit is in the process of workpiece of emery wheel grinding, two diamond of device are measured child contact workpiece surface from beginning to end, the change of workpiece diameter the quantity is adopted measure child, lever, the position of the magnetism core that makes device medium and inductance coil produces opposite displacement, change the change of dimension the change that measures for inductance thereby. Common of active measurement unit says to measure a head, remove a change the parameter that be measured to measure translate into to measure the effect of signal, it is the main body of the measuring instrument. Can separate the aspect that it is sheet from structural principle measurement unit and double dot measurement unit, sheet nods measurement unit to be able to be used at end panel locates or rising with two combination to measure generous diameter to wait; Double dot measurement unit can measure external diameter, internal diameter, chamfer a fight of steps is wide, broad etc. (2) the inductance signal that controls appearance to control appearance to export unit passes Xiang Min commutate, enlarge, give out kibble, essence to grind, light is ground, control a system to grinder to the signal such as dimension, the feed orgnaization of the machine tool is controlled after grinder controls a system to receive signal, achieve the goal that controls work measure thereby. Controlling apparatus is the substantial of active measuring instrument, current control instrument is basic already get rid of departs besides the past the circuit of component, used integrated circuit, some already used microprocessor, counterpoise answer precision, long the function such as stability all has great rise. (3) the advance and retreat of measurement unit of oil pressure actuating device is driven by oil pressure actuating device, after workpiece has been installed, emery wheel advances quickly, at the same time drive oil cylinder also drives active measurement unit to enter survey worker worker. Grinding arrives after dimension emery wheel is fast go back, drive oil cylinder drives active measurement unit to exit survey worker worker, in order to facilitate handlers assembles and unassemble workpiece. Oil pressure actuating device is the join component of active measurement unit and machine tool, be in charge of entering plant or exit survey worker worker, pass the adjustment of orgnaizations of pair of around fine tuning, can make the center of work of the alignment that touch a head of device. Current oil cylinder has vertical and horizontal (decide high according to the center of the machine tool) . By above 3 parts group measures control system and machine tool actively what become to controlled systematic combination to be formed measure actively in grinding treatment process. It is in order to use process of grinding of 3 signal pilot exemple, from emery wheel fast feed enters kibble phase, p1 dot is the signal dot that grinds feed switch to essence of life from kibble feed, p2 dot is grind feed to be nodded to the signal that does not have switch of scintilla grinding feed from essence of life, p3 dot is nodded to retreat knife signal to dimension. The machine tool controls a system to receive these 3 signal to carry out disparate movements respectively early or late from control appearance, finish loop of a grinding. To treatment of high accuracy grinding, general and OK spend the dimension that machines a spare parts control to be in dispersedly 3 μ of 2 ～ ｍ . In recent years, while craft asks dimension precision rises, raise appearance precision even, the control signal dot that asks for this machine tool increases 4 from 3, increase 6 to 5 ～ to nod even. 2. Measure appearance actively measure control (1) to the control of workpiece taper is in the grinding treatment of car component, wait for the work that has many axes way like camshaft, crankshaft especially, measure of requirement axis diameter is consistent, cannot produce bigger taper, use measurement unit of two external diameter commonly to such workpiece, measure way of two end axis, the treatment rate that considers two end is different, obtain the control of pair of dimension and taper through controlling grinding cycle. External diameter measurement unit controls workpiece respectively through controlling apparatus the dimension of two end, will measure the taper that go out to be worth signal to output a machine tool to control a system at the same time, use at dominating the action of emery wheel, finish the control of pair of workpiece taper. (2) to the measurement of workpiece ellipse is used at measuring an axis at present kind the active quantity appearance of spare parts ovality has two kinds, one commonner kind is the diameter that uses the double measurement unit that choose form to measure a workpiece directly, through electric figure computation gives a diameter to differ, the assess that serves as ovality is numeric; Another kind is newest those who roll out use only place to measure a law to detect in machining a process the circularity of workpiece (measure a principle with the radius law of circularity appearance identical) , after passing corresponding to be being measured so that data makes processing, read the circularity that gives work to be worth directly. ① is commonly used the of active quantity appearance that measures ovality the double measurement unit that choose form: Inside buy two differential transformer type sensor, but countershaft kind the spare parts undertakes be metricaled actively. Controlling apparatus is dimension of control axis diameter above all, after grinding of workpiece external diameter approachs formulary numerical value, control appearance begins to measure the ovality of workpiece, use peak value to maintain circuit measures external diameter the the biggest, least value passes data processing, output the size of ovality directly; Be like ovality out of tolerance, will issue signal, will control the nap of ovality by the machine tool. The PULCOM V10 series that new-style and online circularity measures ② to produce Japanese Tokyo nicety with of active quantity appearance controls appearance and form a complete set of the double measurement unit that choose form to use, can measuring workpiece diameter while, use as identical as the radius law of circularity appearance measurement principle, next touchs a head to measure workpiece directly circularity that use device. This signal that measures appearance mirrors speed to be 1ms, workpiece rotate speed is inside limits of 17 ～ 999rpm. Rotate a week, can measure 60 ～ 3600 data, reach wave crest number through screen can show the circularity of workpiece is worth intuitionisticly. Appearance of this kind of control is returned can make choice of is in workpiece treatment arrives before dimension or be about to arrive after dimension measure circularity value. It and traditional circularity rite measure photograph comparing to have the following advantage: In treatment the spot can mirror the circularity that gives work to be worth, reduced the work dynamic load that metric room detects; To a few influences the sudden circumstance to workpiece quality can have monitoring effect in time, like quality of work center aperture bad, treatment reachs mass of blank of undesirable, wool the system of feed of crustaceous, emery wheel that there still is remains when dimension appears breakdown brings about workpiece deflection to wait greatly; Can intuitionistic report gives the state that the machine tool runs, shorten thereby equipment settling time, improve work efficiency. 3. The applied that measures appearance actively the flying development as electronic technology, it is the application of the new technology of the mark with personal computer, make the function of winner momentum appearance and function had great progress, contemporary active quantity appearance overcame the past to undertake to single measure, single course pilot is restricted only, the demand that detects to the product is more and more severe, more and more overall, the application on product line is wider and wider also. Also raised higher level to the respect such as the function of the measuring instrument, precision, stability, satisfied people to measure the requirement that raises increasingly to producing quality. (1) measurement unit of internal diameter is measured before treatment 4 through drive oil cylinder 8 enter survey worker worker, to workpiece 2 undertake internal diameter is measured. Before emery wheel undertakes grinding, quantity appearance already undertook metrical to the internal diameter dimension of wool blank, if too big or the size of wool blank is too small, control appearance will issue signal to the machine tool, stop emery wheel feed, lest the happening of the accident. (2) is measured in treatment this is common grind treatment to measure control process actively. This process basically is to workpiece dimension undertakes controlling. When workpiece of emery wheel grinding, as the accretion of work measure, control appearance basis beforehand the signal dot of set gives out kibble, essence to grind to the machine tool, light is ground, wait for signal to dimension, emery wheel is exited, the grinding that completes pair of work machines a process. In this exemple, one most work measure is spent dispersedly in the day for 3 ～ 5 μ M. (3) the workpiece after is being measured to machine after treatment enters machine hind to survey worker worker, measure a head to undertake metrical to the internal diameter dimension of workpiece by pneumatic, and be proofreaded through the standard regularly compasses undertake null is proofreaded automatically, through A/E gas electricity converter outputs signal control appearance, control appearance general basis the size of work measure, cent becomes 5 groups (+ NG, + OK, OK, - OK, - NG) , the trend that changes to dimension at the same time undertakes judging, the control appearance in giving treatment according to the tendency that dimension changes 6 issue filling attune signal, make its null produces change, control treatment process develops to good way. Carry this kind of kind, can make the machine tool is in continue for long to have the job steadily below the circumstance of unmanned operation. CNC Milling