2. Observation grating feet is undee (two passageways that 1) believes the A of coder, B to date receives digital oscillograph respectively. (2) enters numerical control system, g01 is called to dictate below MDI means, make communicate servo axis to undertake low speed feed moves, by feed writes melody on the right side of " + " key-press (set of default of the fold that write melody is to increase by degrees 10% , press namely " + " key-press, axial feed speed increases by degrees 10%) . (3) adjusts oscillograph, make two passageways synchronous, after axis of observation communication servo moves quickly gradually by low speed, the signal of two passageways is undee, the format scale that fastens with planar coordinate is undee, if pursue,10 are shown. (4) lets communicate servo electromotor to turn reversely, the signal that watchs two channels is undee, and the format scale that to in an attempt to shows 8 times is undee. (5) receives the Z photograph signal of coder a channel of digital oscillograph. (6) enters numerical control system, g01 is called to dictate below MDI means, make communicate motion of feed of servo axis low speed. (7) adjusts oscillograph, observe Z believes date is undee, and the format scale that to in an attempt to shows 8 times is undee. (8) uses similar methodological observation, and signal of photograph of A of scale grating feet, B, Z is undee. Graph format of 8 scale weaveform 5, knowledge is linked 1. Rotate transformer rotates transformer weighs resolver again, it is the electrical micro-machine that a kind of control uses, the device of a kind of indirect measurement of the telegraphic date that it alternates mechanical corner with this corner shows some function to concern. Likeness of type asynchronous electromotor is circled with 2 looks line on the structure, by stator and rotor composition. Stator winding is the former edge of transformer, rotor winding is the deputy edge of transformer. Excitation report crimp arrives on rotor winding, inductive electromotive force is outputted by stator winding. Commonly used excitation frequency is 400Hz, 500Hz, 1000Hz and 5000Hz. Rotate transformer structure is simple, behavioral delicacy, do not have special requirement to the environment, safeguard convenient, output signal range is big, interference rejection sex is strong, the job is reliable. Accordingly, apply extensively on numerical control machine tool. The change coming back that applies normally is pressed implement for 2 extremely rotate transformer, each have two mutual and perpendicular winding in its stator and rotor winding. Additional, still a kind of multipolar change coming back is pressed implement. OK also extremely logarithm mixes less extremely logarithm rotates two kinds much transformer is done go up in a magnetic circuit, install inside a housing, form " thick measure " and " essence of life is measured " electric gearshift double passageway detects device, use at high accuracy testing system and synchronous system. The basis rotates the working principle of transformer, rotate transformer detects as the position device has kind of two kinds of application: Kind of photograph of ancient bronze mirror and ancient bronze mirror means. (Way of work of photograph of 1) ancient bronze mirror is rotating the two-phase orthogonality winding of transformer stator (sine is mixed with S and Yu Xian expresses with C) , call sine winding and cosine winding to go up commonly, input amplitude respectively equal, voltage of excitation of two-phase of T of ω of TUc=Umcos of ω of Us=Umsin of voltage of excitation of the sine with same frequency, cosine is in rotor winding electromotive force of meeting generation reaction. According to linear overlay principle, in rotor winding inductive voltage is U=kUssin θ machine + KUccos θ machine machine of θ of =kUmcos(ω T- ) among them K is transformation ratio, by type 4-10 the phase angle of knowable induction voltage is equal to the machine of mechanical corner θ of rotor. Because this wants to detect only,give rotor to output the phase angle of voltage, knew the corner of rotor, and rotate the rotor of transformer is together with servo electric machinery or transmission shaft join, can carry out the linear displacement of the component or angular displacement in order to get thereby. (2) ancient bronze mirror working way is connected respectively to two winding of stator on phasic and frequency, identical but amplitude is different, namely T of electric Sin ω is in the θ of TUc=Umcos of ω of Sin of report of θ of excitation voltage Us=Umsin of amplitude modulation get inductive voltage is U=kUssin θ machine on rotor winding + machine of θ of Sin of report of θ of T(sin of ω of =kUmsin of KUccos θ machine + report of θ of Uccos of Cos θ report) =kUmcos(θ report - θ , it is the report of electric horn θ that revises cost of voltage of excitation amplitude modulation ceaselessly, make dog the change of θ machine, measure inductive voltage amplitude to be able to get mechanical angular displacement θ machine. 2. Inductive synchronized should synchronized and rotate transformer is same, it is to use electromagnetism coupling principle, the position that changes displacement or corner into telegraphic date detects device. Substantial, inductive synchronized is multipolar rotate of transformer develop a form. What inductive synchronized presses its motion form and configuration is different, can divide to rotate type (or disk type weighing a circle) with straight formula two kinds. Former with will detect corner displacement, use at accurate revolving stage, all sorts of circumgyrate servo; Latter is used detect linear displacement, use at large the automatic fixed position with accurate machine tool, displacement number shows and in numerical control system, both job principle and working way are same. (1) the structure of synchronized of straight formula induction is like the structure of inductive synchronized the graph is shown 9 times. Inductive synchronized by stator and slide two parts are comprised. Scale and slide serve as matrix with high grade carbon steel normally, choose commonly guide magnetism material, its coefficient of expansion installs with place as far as possible advocate matrix close. Scale and slide parallel are installed, and hold certain clearance. Scale surface is made have successive and planar winding (the adhesive that uses insulation on matrix affixes Copper Foil, consumed is engraved or chemistry corrodes winding of plane of mouth of form of set prescription of honest legal system) ; An aluminum foil often is stuck all round the winding in slide, prevent static, make on slide have winding of two groups of section, call sine winding and cosine winding respectively, , photograph of these two paragraphs of winding staggers in the space to scale winding the pitch of 1/4, pitch expresses with 2 τ , component of the scale when installation and slide component installation are in of the machine tool be not moved and on mobile component, for example workbench and lathe bed, slide installation is on the machine tool, natural ground connection. When the job, when in slide the either winding in two winding increases incentive tension when, as a result of electromagnetism induction, in scale winding meeting induction gives the inductive voltage of same frequency, pass the measurement of pair of induction voltage, OK and accurate measurement gives displacement amount. Inductive synchronized uses the change of inductive voltage to undertake the position detects namely. Graph the structural principle of synchronized of induction of 9 straight formula (2) the application of inductive synchronized and rotate transformer is same, type of photograph having warning and ancient bronze mirror type works two kinds means, principle also identical. (3) the characteristic 1) precision of inductive synchronized has high because of the pitch error of scale compensate action on average oneself, so the precision of rule itself can be done higher. Sharp reaction synchronized is measured to what machine bed moves is to be measured directly, do not pass any mechanical gearing, measure precision to basically depend on the precision of rule. The sensitivity of inductive synchronized (or weigh resolution) , depend on the rate that a cycle has electric fractionize, of sensitivity raise the limitation that a confusion of voices is believed to compare in electronic fractionize circuit, want to have elaborate design and the interference rejection step that take rigor to circuit only, can reduce electric noise very low, gain very tall stability. 2) measures length unlimited when should measuring length to be more than 250 ㎜, can use many scale to receive long, interval of photograph adjacent scale can use slip gauge or laser measures chief instrument to undertake adjustment, make overall length spends the length the biggest error that accumulates an error to not be more than single block scale. The journey arrives for a few meters in a few meters medium-sized or large machine tool, measure of workbench displacement point-blank, great majority uses synchronized of straight formula induction to come true. 3) is right of the environment suit to be mixed higher because of substrate of inductive synchronized metal the heat with cast-iron lathe bed bilges coefficient close, when temperature changes, still can obtain taller repetition precision, additional, the dimensional coupling parts of an apparatus of contact of inductive synchronized dispute, defend to feet face so the demand is low, and optional choose is able to bear or endure the blame permeability painting with lukewarm good performance makes covering layer, strengthen inductive synchronized fight lukewarm water-vapor proof ability. 4) is safeguarded simple, life grows the scale of inductive synchronized and slide each other to be not contacted, because this does not have any attrition, wear away, service life is long, and the problem such as ageing of beardless and afraid component. Additional, the interference rejection capability of inductive synchronized is strong, craft sex is good, cost is inferior, facilitate duplicate and produce group by group. 3. Feet of magnetism feet magnetism calls magnetism bar again, it is detecting element of position of numerary of wave of magnetism of a kind of computation. Can use at be being mixed point-blank of corner measure, its advantage is precision duplicate and tall, simple reach installation to go to the lavatory etc, and have better stability, commonly used in the circumstance with smeary, more dust. Accordingly, all sorts of measurement is mixed in numerical control machine tool, accurate machine tool got be used extensively on machine. Graph structure of 10 magnetism feet and feet of working principle magnetism by magnetic staff guage, magnetic head and detect circuit composition, its structure is shown 10 times like the graph. Magnetic staff guage is to be in blame guide on the matrix of magnetism material, use Tu Fu, chemical deposit or eletroplate a very weak magnetic data, make with the means that employs magnetism apply layer magnetizes the magnetization signal that changes into equal pitch cycle next. Magnetizing signal can be pulse, also can be sine wave or saturated magnetism wave. The pitch that magnetizes signal (or periodic) have 0 commonly. 05 ㎜, 0.
10mm, 0.
20 ㎜, 1 ㎜ a few kinds. Magnetic head is to undertake magnetism, the parts of an apparatus that report changes, it detects the magnetism signal that reflects the position come out, change into telegraphic date to be carried detect circuit. Magnetism rule uses job of the principle that record magnetism. Wave of the square wave that will press certain cycle to change with the magnetic head that record magnetism first, sine or transcribe of electric pulse signal are on magnetic staff guage, as measure fiducial. When detecting, the magnetism signal that gets on magnetic staff guage with the magnetic head that pick up magnetism is changed into telegraphic date, send again detect go in circuit, measure magnetic head photograph to the displacement of magnetic staff guage use a number to show, transmit numerical control system. 4. Coder of pulse coder pulse is one kind rotates type pulse generator, turn mechanical corner into electric pulse, it is a kind of commonly used angular displacement sensor. Also can make tachogenerator at the same time. (Cent is the classification of 1) pulse coder and structural pulse coder photoelectricity type, contact and electromagnetism induction type 3 kinds. The precision of photoelectricity type and dependability excel is other two kinds, because coder of photoelectricity type pulse is used only on machine tool of this numerical control. Photoelectricity pulse coder gives pulse to count by every transmit more or less will divide, have a variety of type. The most commonly used photoelectricity pulse coder on numerical control machine tool sees a table 2. Of pulse coder choose the pitch according to guide screw of ball of numerical control machine tool to decide. Express coder of pulse of generator of 2 photoelectricity pulse every move momentum (Mm) pulse coder every move momentum (Mm) 2000P ／ R2, 3, 4, 6, 83000P ／ R3, 6, 122500P ／ R5, the structure of coder of pulse of 10 photoelectricity type is shown 11 times like the graph. In a disc circumferential on quarter have wait for span strain line, cent is transparent with opaque part, call round grating. Round grating and working axis rotate together. As opposite as round grating, parallel places a fixed sector chip, call demonstrative grating, make above have differ two slit of 1/4 pitch (differentiate to slit) . In addition, still have slit of a null (every transmit gives a pulse) . Pulse generator connects contact through the cross or key and servo electromotor are linked together. When round grating rotates, the light passes through the strain line part of this two grating, form the stripe of alternate with of light and shade, be accepted by photoelectricity component, alternate measure pulse, its resolution depends on the number of circuit strain line of round grating and the fractionize multiple that measure circuit. Pulse coder is main specifications sees a table 3. Express 3 pulse coder ± of 5V of main specifications power source 5% , ≤ 0.
35A temperature limits 60 ° C outputs 0 ～ signal A, ; B, ; Z, axial frequency is moved 0.
02mm every turn pulse is counted 2000, 2500, ＜ of 3000 rotor inertia 5.
± of 5V of power source of 7kg · Cm2 5% , ≤ 0.
35A temperature limits 60 ° of 0 ～ damp of Min of ／ of 2000r of C top rotate speed turns Cm of · of the 8N that be apart from ＜ pursues weaveform of output of 12 pulse coder becomes the knot composition of a picture of coder of pulse of 11 photoelectricity type when round grating and working axis turn together, the light passes through the strain line part of two grating, form the stripe of alternate with of light and shade. Photoelectricity component accepts the smooth signal of alternate with of these light and shade, change the telegraphic name that is alternant commutation. This report signal is two groups of approximate Yu Zhengxian the voltaic signal A of wave and B, if pursue,12 are shown. A and B signal are phasic differ 90 ° , become quadrate wave via enlarge and whole deformation. Carry the signal of two grating, still have " every turn pulse " , call Z photograph pulse, this pulse also must come through afore-mentioned processing. Z pulse uses the datum mark that generates a machine tool. The pulse later is sent tally, the amount according to pulse and frequency can measure the corner that gives working axis and rotate speed. Its resolution depends on the pen number of round grating and the fractionize multiple that measure circuit. (Coder of pulse of 2) absolute value and coder of increment type pulse are different, absolute value coder is take encode through reading dish the position that the design that go up determines an axis. Code dish read take means to type of contact, photoelectricity and electromagnetism type wait for a few kinds. The most commonly used is photoelectricity type coder. Of coder of photoelectricity absolute value code dish of principle graph and knot composition of a picture are like a graph 13 are shown. In graph 13a, code dish on have way of 4 bar code. The code even if pile up dish of homocentric circle that go up. According to binary distributinging rule, machine path of every bar code into transparent the form with opaque alternate with. Code dish a side installs illuminant, another side installs the photoelectric cell that a radial arranges, every photoelectric cell aims path of one bar code. Pile up when illuminant illuminate dish when, if be transparent area, criterion the light is accepted by photoelectric cell, transform telegraphic date, output signal is " 1 " ; If not be transparent area, photoelectric cell does not accept the light, output signal is " O " . The axis that be measured drives a code to circle when turning, the information that photoelectric cell exports represented corresponding position of the axis, namely absolutely position. Graph photoelectricity of coder of 13 photoelectricity absolute value codes dish use Grey to pile up encode mostly dish, code of case thunder yardage sees a table 4. The characteristic that Grey piles up is each photograph adjacent a binary system is changed to count only between the number, such, although make,mix installation is very not accurate, the error of generation also is lowest only at most one digit. 4 binary code dish the smallest angle that can differentiate (resolution) 24=22 of ／ of ° of the =360 that it is α .
Talk of 5 ° code is more, resolution is smaller. Current, it is OK to pile up dish of code to accomplish 18, the smallest angle that can differentiate is 218=0 of ／ of α =360 ° .
0014 ° express 4 encode dish case thunder piles up digital angle binary system Grey piles up decimal angle binary system decimal O0000000008 α 0001000119 α of 100011008 α 10101111103 α of α of 1001110192 α 0010001121O 10111110114 α of 00110010311 α 11001010125 α of 01000110412 α 11011011136 α of 01010111513 α 11101001147 α of 01100101614 α photoelectricity of 01110100715 α 1111100015(4) , will detect signal feedback gives numerical control the system. Its feedback to have two kinds of kind to numerical control system: It is to suit belt add the reversible tally that reduces computation demand, form add count pulse and decrease computation pulse; 2 it is to get used to the tally that has computation control and computation demand, form direction to control signal and computation pulse. CNC Milling
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