oc 621.314.5:621 919.309 AC SPINDLE DRIVE SYSTEM FOR SMALL-SIZED MACHINE TOOL FRENIC 5000M (0) FOREWORD For driving spindles of smallsized lathes or milling machine, the standard cage rotor type induction motors have been used conventionally, and speed change was ceffectuated by changing the pulley ratio or through gradual change by pole-number changing cage rotor type induction ‘motor as the case may be. But with a view of miniaturizing of machines and improving the functionality, electric vari able speed spindle drive system has come to be desired. For coping with such demands, Fuji Electric has developed and is now mass producing high performance and maintenance free AC Spindle Drive System FRENIC 500M. This AC Spindle Drive System consists of exclusively designed cage rotor type induction motor and PWM (pulse- ‘width modulation) inverter, but different from general purpose AC variable-speed motor, in order to improve accelerating/decelerating performance and making speed higher of shortening the working cycles, itis designed and constructed as an optimum product for small-sized machine ‘tools. Fig. J showsits outer view In the following, features, specifications and per- formance of FRENIC 5000M are described. Fig. 1 FRENIC S00OM ser AG spindle drive system ‘Yasushi Yamakawa Hiroshi Furuya Z| FEATURES ‘The features of FRENIC SOOM AC Spindle Drive Sys- tem ae the following, 1) Short accelerating/decelerating time In a wide range of constant torque and constant out- put, by enlarging overcurrent capacity of the drive unit, and control giving accelerating/decelerating command by curve suitable for the torque generated by a motor, shortening of accelerating/decelerating time is attained. This contributes greatly to the improvement of work efficiency of small-sized machine tools as automatic lathe. 2). Wide adjusting speed control By means of a specially designed motor and inverter, ‘a speed control range as wide as 150 to 4,500 rpm (constant, torque + constant output range) can be obtained for the operation, 3) Smooth reversible operation and stopping As shockless progressive/reverse operation switchover system is adopted, a smooth reversible operation of the spindle can be attained. Also, for stopping, a DC breaking under 0.5 Hz will be applied for obtaining sure and quick stopping operation, 4) Interface and option for NC machine tool AAs an interface in full consideration of NC equipment, important functions as detection of designed speed at- tained, speed zero detection and override setting are equip- ped as standard equipment. ‘As an option, a frequency meter, D/A converter for coping with the digital speed command, and simplified orientation system for stopping at fixed point with a preci- sion of 2 to 3° of the spindle are available. (SPECIFICATION 3.1. Standard specifications Table 1 shows the standard specifications, 1) Rated output Five models ranging from 1.5 to 7.5 kW are made as standard equipment, but upon a special request, construc. tion up to 11 kW is possible.2) Maximum speed able 1 List of standard specifications rele t eee |As the standard prectice for all models, 4,500 rpm is Seriesname FRENICS000M ‘the maximum speed, but upon a special request, construc Ser Te Teas ass ak tion up to 6,000-zpm equipment is possible. Consnous eating output | Ts 3) Input power supply | meat [as | 22 [aa | ss [75 As the input voltage of 200 to 230 V+10% is tolerable, Based speed pm) _| 1,500 (Synchronous speed) the equipment can be used simply by switching an internal oe selector switch even for the areas where 230V power pees | 2800 Gy supply is used as in the United States. Model MPF post norfausfnalos| Sy Continsousfaneapasty” Io.97 1.43 [20 [357 [a7 In order to shorten the decelerating time, regenerative —__t discharge circuit will be equipped as standard practice and ._ [oo (igim?) [o1022|0.028[0.068)o1 [ox discharge resistance equivalent of 10% ED is supplied 2s 3 [Approximate weight ka) | 22 | 26 | 46 | 60 | 74 accessories outside of the inverter unit = | cooing fan capacity 13,500 & | Vibation V0 or ess 3.2 Option F | Noise 75 4B (A) oF 1) D/A converter Overload 130%, one minute Two ype of printed boards ae eat for oo Paracame oe EID coping with 12-bit binary and BCD 2- [o during ¢ machine stop, it will be accelerated once to ORT ae 3, 200/220.230 Val0e, speed, then stops at designed position wer sup blan ne ie Generated heat value QW) | 120 | 150 | 220 | 300 | 00 Approximate weights) {| _10 eis Fig, 2. Simplified oriantation operating time chart Main decut stem | TIShsstor pe sinusoidal wave a fui ica ys BWM ype WWVE inverter le "Reh tang rove tng) Control system Vik control cee Reversible operation Golected / zg [Omtnesysem | Ant Sa : Danie baking 0% ED oe al & | Braking system rating) and DC braking (035 Ho a oe ores) * a ORF comand | Frequency control (05~150 He Q00 He ako ne posal) OF gd f cc Frequency preciion | 05% @5:10°O) ee coed sand) “10 or 10Vimaximam Posten sa Prequency setting voltage | $LOV.o! “10Vi cls. if ‘Accelerating/ decelerating | Soft sart/sft stop (~10 seo gt ta sa! Sistem Tortem setting) (erence fin) ‘Munsell 1.2 semi-gloss (Cove: 7 — Color of paint Munsell 1P85/1-3) converter, simplified Orton venient / Indoors, altitude; 1,000 m or ls Installing place ; pe = G@_ CIRCUIT COMPOSITION Ambient temperature | 0~#50°C, 20~90% RH (No : na hui ondemstion alowed) Fig, 3 shows the citcuit composition. Main points of [AC Spindle Drive System for Small sized Machine Tool FRENIC 000M the composition are explained in the following, 113Fig, 2 Circuit composition oe : | ee : es) ae et mt ne | eter to i ei : 8m ey Sey u se | eh tn sand es ‘bie tan caren Signs! 3 ie | a readin | i 2 } = Ove. & TEs tomo ORT Conmand —)—) 3 vo es i ar ie Jeet Ste isle oe resmcry anmmiatoe [eer Fig. 4 Acceleration/secoleration characteristics (Motor only) 4.1 Main circuit a The cious stuotured with the same design concept as that of FUII ELECTRIC'S general-purpose inverters ‘00% That is, it 9 designed to have a larger overcurrent capacity (200%), and it is equipped with a regenerative discharge cireut for intensifying the braking torque as standard equipment 4.2 Control circuit The main control circuits except for interface circuit, base drive circuit and protective circuit are covered with software by high-performance 16-bit microcomputer. So that number of parts is reduced and reliability is much improved The power supply for the control circuit is obtained from DC intermediate circuit of the main cireuit, and it ; has a performance of allowable momentaneous interruption acl time of more than 100 ms (5) OPERATING CHARACTERISTICS Fig. 4 shows an oscillogram of accelerating/decelerating operation consisting of Acceeration-Reverse Operation — Stop. The speed for both way operations (progressive) reverse) is 4,500 rpm, but current-limiting acceleration is Ft peed (rom) 4 Vol.31 No.3 1985 FUJI ELECTRIC REVIEWFig. 8 Spindle motor vibration characteristics cer AD IEE tom icin of tat at Brocton of @ torent crcton) oh arate () Roteng sed (com) [ carried out even for constant output range more than 1,$00 rpm. Switching over between progressive/reverse rotations is carried out by 0.5 Hz, so that smooth and natural changeover operations can be attained from the [AC Spindle Drive System for Smallsized Machine Tool FRENIC S00OW point of view of current waveform, Fig. 5 shows the results of noise measurement. In the highspeed operation range, which is the most frequently used region, particulary quiet operating characteristics are obtained. Fig. 6 shows the results of vibration measurement in the whole operating range measured in three directions. An amplitude of 5 um is attained in allover range. (5) SUMMARY We have in this report introduced newly developed FRENIC SO00M excellent in cost performance as the spindle drive system for small-sized machine tools. The newly developed system enjoys 2 big popularity since it expanded range of machine type selection as machine tool spindle driving system, used in combination with high-performance superior-order series SO00V2|VEI2. We intend to improve and expand the manufacture of this type of machine so that we ask for kind suggestions and instructions from the users. 115