Brand-new concept of demarcate of gear high accuracy

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Courtyard of German nation capacity familying livelihood (PTB) developed a kind brand-new demarcate concept, can use at example of product of high accuracy demarcate gear (standard component) , this is the key that the quality that will satisfy gear manufacturing industry to grow increasingly through reducing the inaccuracy of demarcate of current gear example to be spent surely asks and strides one pace.  in recent years national level and international standard (like AGMA and ISO standard) the inaccuracy that all asks gear makes a manufacturer consider to measure is spent surely, for this, gear maker needs to reduce what what set on former blueprint to make common difference. Subsequently, need the demarcate of high accuracy, in order to make uncertainty of measurement as far as possible small and production public errand as far as possible big. The measurement unit that  article place describes is based on coordinate to measure machine (CMM) , deploy workbench of high accuracy circumgyrate on its, be used at range finding dog type laser interferometer (TI) evaluate software with authorized. Whole those who survey process and software test is fiducial (standard) the measurement technique that algorithmic place uses is developed by PTB. The new concept of  gear demarcate and plant gear measure the measurement with constant very tall need precision, the noncombatant duty that place of gear of nowadays high quality sets often falls in metrical inaccuracy to spend limits in, gear (product) quality is considered as no longer reliable. The inaccuracy that measures in industrial domain is spent surely in, having quite large part is caused as a result of the sample plate that demarcate of devoid high accuracy passes, this example has the complex figure of industrial gear. And the country is fiducial now the appearance of example and industrial product gear are very different, this makes be being delivered through measuring a result to realize high accuracy quite directly is impossible. Its are as a result, arrive from metric courtyard workshop, uncertainty of measurement increases ceaselessly. Consequently PTB developed a kind of new concept, it can be used at the direct demarcate of product example. Of  involute gear all and important survey a project (if tooth profile, teeth directional and pitch are measured) it is by linear circumgyrate moves and a linear and sharp movement is comprised, the characteristic with this kinematic gear is used to the effect that reduces error of instrument slideway geometry.  is brand-new the principle that measurement unit of high accuracy gear is based on is, try to obtain the most accurate measurement result. This concept combined CMM but flexible, have a tradition to measure politic advantage, the demarcate precision that allows three-dimensional product example and nowadays 2 dimension country is fiducial example demarcate precision is same. New gear measurement unit is based on 4 parts (component) : The Cartesian type CMM that tall nicety, contact measures, circumgyrate workbench, dog type laser interferometer (TI) and evaluate software via what affirm, the circumgyrate workbench of high accuracy is compositive the measurement at CMM workbench. The commodity photograph that goes up with the market is compared, the geometrical error of this circumgyrate workbench is very small, and, no matter be CMM or circumgyrate workbench,need to be amended through the number (compensation) . The TI that  develops by PTB, its stimulate beam of light to dog the illuminator that installation stands by probe to carry a department, this makes the precision that stimulates numerical value of the length on direction of beam of light achieved the precision of interferometer.  detects the position is the reading that gets from quarter feet by CMM and circumgyrate workbench position is mixed dog laser interferometer measures the synthesis that gets is apart from to get. All what information represented measurement point measurement decide too that what from the instrument each component place obtains (redundant) digital information, patent algorithm is used at finding to improve the position of precision. Temperature is passed to the influence of CMM and TI after detecting, amend. Whole measure a process to measure strategy and evaluation algorithm to be developed by PTB, corresponding software comes true by Java. Every data of single measurement point with static mode (blame scanning mode) get, the reading of all components is controlled by CMM and read at the same time take.  maths setting raises precision detect the position is the reading that cuts foot through CMM and interferometer the interval that measures bit by bit is calculated and get, this requirement is referenced (fiducial) positional X0 is informed beforehand. Want to decide X0, CMM must move 4 positions (X1... X4) , and they must be absent same and linear, planar or spherical on. In Xi of every CMM position, measure so that be apart from Di, what mix through error squared is the smallest change can get sealed position X0. After the position of TI is firm, can undertake actual measurement. In measuring a process every time, the signal of exploration system, instrument engraves feet and interferometer length information to be recorded to come down at the same time.  raises the computation of ′ of X of precision CMM position: Assume to taken positional X is read to differ on quarter feet of the positional X ′ that raises precision and instrument Δ X, and their deviate (consult) the is apart from D and D ′ poor value of standard position is Δ D, carry ′ of X of high accuracy position to also concern ′ of X of ｜ of ＝ of ′ of D of ′ of D of Δ of D+ of ＝ of ′ of Xd of Δ of X+ of ＝ of  X ′ with interferometer position X0 - the maths that the coordinate that X0 ｜  raises precision is worth and is apart from a value to be able to pass function of a target, give ′ of D of distance measured value great weight namely and give positional X ′ little weight. The reciprocal value that the distance Ud of the reckons inaccuracy is spent surely reciprocal cost that CMM cuts feet position Up and interferometer estimates to inaccuracy is spent surely presses type chooses D2/Ud2 of Δ of Z2/Up2+ of Δ of Y2/Up2+ of Δ of  Δ X2/Up2+ reasonably → Min in principle, use any digital methods to be able to undertake optimization, any directional information did not get in be being measured as a result of TI, the ability on the linear way that the position measures what do not decide to decrease to explore position of system and interferometer in join only gets. If the inaccuracy of original position X decides degree of hypothesis,be globose, the inaccuracy that raises ′ of precision position X is spent surely measuring tooth profile lieutenant general to be ellipsoid form.  dogs laser interferometer the distance uncertainty of measurement of TI is a system the main factor that in beam of light the inaccuracy on square line spends surely. Dog the stability that appearance circumgyrate chooses is particularly important. Because business uses laser to dog,the distance of appearance measures inaccuracy to spend short of inferior micron class, PTB developed a kind of new tall nicety to dog interferometer. In this design, installation is based on to consult fixedly in the interferometer on versatile connect (fiducial) spherical motion, the one side that pushball face regards interferometer as only is fiducial (consult) lens cover is effective. Because used this job principle, the radial of circumgyrate orgnaization shafting or side direction deviation do not affect measured precision. The accuracy that  TI length measures basically depends on fiducial and spherical quality and its repetition in dimensional position precision. Come to reduce its effect the smallest, fiducial and spherical appearance error wants little at 30nm. Its installation is on an invar column, cause any displacement in order to because heat expands,avoid, temperature of ambient conditions such as, atmosphere and relative humidity undertake monitoring, in order to amend laser signal. Because TI diameter is 7kg of 250mm of 200mm, height, weight only, reason can put mesa of park CMM job directly. Fiducial (consult) the evaluation with new software (plan value) the measurement of parameter of geometry of example of the product that software can define pair of long shape according to what normally gear evaluates standard and directive file gear result plan value. In addition, this software still can use the numerical value that compares PTB standard software to get and industrial group computation to get the difference between numerical value, so that be versed in,industry affirms its product precision.  is opposite for new method of test and verify the measurement of example of gear involute tooth profile the effect, undertook comparative metrical. Example of fiducial tooth profile has the state quality of advanced course appearance and the very little measured value that do not spend certainly, this new to the evaluation measurement technique offerred wonderful condition. Measure exhibit a principle to undertake according to gear.  from measure a result to be able to see, the consistency that the calibration value of example and new unit measure an outcome is very good. Through undertaking comparative as a result with the measurement of general CMM, prove new method improved uncertainty of measurement greatly. The uncertainty of measurement of new measurement unit satisfied the quality requirement that raise, it already was used at example of demarcate product gear nowadays. (pick from " the tool is looked into " Xie Huakun interpret) CNC Milling CNC Machining