One, the demand of stone material engraving tool to electric machinery of main shaft electric machinery and servo is diverse the requirement of Shicai engraving tool to feed servo electric machinery basically is:
(1) physical characteristic: Of requirement servo electric machinery fast fall the demand that big;(2) of all, stiffness answers quickly: This is machined in outline, special the requirement when old to curvature treatment boy or girl friend undertakes high speed machines is stricter;(3) timing scope: Material of the cutting tool that this can make numerical control machine tool applies to all sorts of differring, treatment pledges; suits to machine the output torsion with craft certain;(4) at what all sorts of differring, the overload torsion with ask certain. The property with laden machinery of machine tool feed basically is the obstruction of the attrition force that overcomes workbench and cutting, because this basically is the property of " of " constant torsion.
Basically be to the requirement of main shaft electric machinery:
(1) outputs power enoughly, the property of main shaft load of stone material engraving tool is approximate at " of " constant power, become namely when the main shaft rotate speed of the machine tool is high, output torsion is lesser when rotate speed of; main shaft is low, the scope of property;(2) timing that output torsion big; asks main shaft actuating device wants to have " of " constant power namely: Material of the cutting tool that applies to all sorts of differring to assure stone material engraving tool, treatment pledges; suits to machine craft at what all sorts of differring, electric machinery of requirement main shaft has certain timing limits. But precision of speed of lower than feed to the requirement of main shaft;(3) : General requirement static difference is spent be less than 5% , higher demand is be less than 1%;(4) fast: Main shaft actuating device also is used on fixed position function sometimes, this asks it also has certain fast sex.
The dynamical system no more than of stone material engraving tool is a pace enter electric machinery and servo electric machinery, both control pattern is very similar, it is to pass pulse is strung together and directional signal is controlled, but two performance characteristics is put in the difference with bigger move.
1. moving function is different. The pace is open loop control into electric machinery, exorbitant or the frequency that start is laden too big easy appear the phenomenon that loses pace or locked-rotor, the rotate speed when stopping is exorbitant easy the phenomenon that has appeared to rush, control precision to assure its so, should have handled litre, fall fast problem. System of communication servo drive is closed-loop control, driver can feedback to electric machinery coder directly signal undertakes sampling, interior makes positional annulus and speed ring, won't appear commonly the lose a condition or rushs too appearance that the pace takes electric machinery, control function is more reliable.
The precision with both 2. is different. Two interblend add up to type situation to be 3.6 ° , 1.8 ° commonly into horn of electric machinery step pitch, the control precision that 5 interblend combine type situation to be electric machinery of servo of; of 0.72 ° , 0.36 ° commonly into horn of electric machinery step pitch by back end of electric machinery axis rotate coder assures, to bringing a level for the electric machinery of 2500 lines coder, major drive interior used fourfold frequency technology, its pulse equivalent is 360 ° / 10000=0.036 ° . To bringing the electric machinery of 17 coder character, every receive driver 217=131072 pulse electric machinery turns circuit, namely its pulse equivalent is 360 ° / 131072=9.89 second. It is step pitch horn the pulse that takes electric machinery for the pace of 1.8 ° is equivalent 1/655. Say simply even if precision of control of servo electric machinery is more than 600 times what the pace enters electric machinery.
3. overload ability is different. The pace does not have overload capacity commonly into electric machinery. Communication servo electric machinery has stronger overload capacity, it has speed overload and torsion overload capacity. Its are 3 times what torsion is rated torsion bigger, usable Yu Ke takes the inertial moment that inertial load is starting the instant. Because do not have ability of this kind of overload,the pace enters electric machinery, often need to choose the electric machinery of bigger torsion when type selecting, and the machine does not need so big torsion again during regular job, appeared the phenomenon with wasteful moment of force.
