Exceed magnetism to send the research of system of drive of adjustable small displacement

Time:2023-06-20 10:22:46
Click:215
source:EAMOM CNC Machining

Summary: Exceeding magnetism to send adjustable material is material of a kind of when in recent years development rises new-style function, have below room temperature meet an emergency is measured big, energy density is high, electromechanical lotus root adds up to coefficient to wait for character greatly. The article analysed the drive principle that exceeds magnetism to send adjustable material, introduced to exceed magnetism to extend the composition of system of drive of adjustable small displacement and working principle. Waited for function index to undertake the experiment studies to precision of the stretchy quantity of this system, small displacement. Technology of 1 introductive small displacement is one of crucial technologies of accurate treatment and superprecision, be applied extensively in superprecision, in order to adjust the tool, treatment dimension precision that assures workpiece and exterior quality. If exceed accurate turning in, of diamond cutting tool cut deep fine tuning to want to assure to be in inferior the precision of micron class: In exceeding accurate grinding, the small feed of emery wheel asks to achieve hundred micron; With Yu Chao the error of accurate machine tool compensates minim feed orgnaization, demand of its displacement precision is higher. In recent years, as large-scale the rapid development with VLSI, what small machine studies is arisen, and to it the urgent need of corresponding small operation, raised taller and taller requirement to small displacement technology, ask precision of its fixed position is tall, answer speed efficiency of fast, changeover density of tall, power is big. Current, as the occurrence of material of a few new-style functions, developed a new field again for small displacement and the research related its. The article is emphasized exceed magnetism to send adjustable material to be based on -- a kind of new-style report (magnetism) , the system of small displacement drive of material of mechanical energy changeover undertakes study. 2 exceed magnetism to send department of iron of rare earth of adjustable material and its drive principle to exceed big magnetism to send adjustable material is a kind of new-style, efficient magnetism (report) one mechanical energy changes material, it is high temperature of glow of permanent magnetism of afterwards rare earth, rare earth, rare earth after superconductive material material of function of another arisen kind of rare earth, be by Dr. Clark of center of American surface weapon at 20 centuries compound of iron of 3 yuan of when there is very big magnetism to send adjustable coefficient below room temperature and low magnetic field when discover above all at the beginning of 70 time rare earth. With the material that suppress report (PZT) and traditional magnetism send adjustable material nickel, auger wait for photograph comparing, exceed magnetism to send adjustable material to have distinctive property: The value of meet an emergency below room temperature is very great, the 40 ～ that are nickel 50 times, the 5 ～ that are the pottery and porcelain that suppress report 8 times; Energy density is high (14000 ～ 25000J/m3) , the 400 ～ that are nickel 500 times, the 10 ～ that are the pottery and porcelain that suppress report 14 times; Electromechanical lotus root adds up to coefficient big (0.

72) ; Answer speed fast (achieve µs class) ; Output muscularity, can amount to 220 ～ 880N. 1.

Cooling water is in charge of 2.

Mouth giving water 3.

Can control constant current source 4.

Water inlet 5.

Exceed magnetism to send adjustable material 6.

Press spring beforehand 7.

Be out of shape part 8.

Permanent magnet 9.

Guide magnetic body 10.

Drive coil pursues the character that 1 exceed magnetism to send diagram of principle of adjustable material drive to exceed magnetism to send adjustable material can send adjustable equation to express by magnetism, type (1) and type (2) is to consider to heat up metabolic magnetism to send adjustable equation. In E=sHs+dH+aT(1)B=ds+msH(2) type: Intensity of the strain that E, H, B, S and D show to exceed magnetism to send adjustable material respectively, average magnetic field, magnetic induction intensity, internal stress and magnetism send coefficient of adjustable meet an emergency; The hot coefficient of expansion that A and T indicate to exceed magnetism to extend length of adjustable data unit respectively and average temperature rise; SH and Ms express to exceed magnetism to send the flexibility coefficient of adjustable material and magnetism conductance respectively, they suffer the effect of magnetic field intensity and stress respectively. Graph 1 it is the author the drive principle sketch that the drive performance place that sends adjustable material according to exceeding magnetism uses. In the graph, guide magnetic body 9, permanent magnet 8 with exceed magnetism to send adjustable material 5 composition close magnetic circuit, in order to reduce magnetism leak; Press spring beforehand 6 to exceed magnetism to send adjustable material 5 it is certain to offer beforehand pressure, in order to increase its stretchy quantity; Exceed magnetism to send adjustable material the drive magnetic field of 5 is You Yongjiu magnet of 8 generation slant buy magnetic field and drive coil the overlay of metabolic magnetic field of 10 generation and into, can control constant current source through the change the drive electric current of 3 in order to produce corresponding small displacement; To as a result of,be restrained drive coil of 10 give out heat and cause exceed magnetism to send adjustable material the heat of 5 is stretchy, the temperature rise control that uses the method that knows constant temperature water to will exceed magnetism to send adjustable material is inside certain limits. The composition of 3 systems and working principle graph the compositive principle block diagram that 2 exceed magnetism to cause system of drive of adjustable small displacement pursues 2 it is the compositive principle block diagram that exceeds magnetism to cause system of drive of adjustable small displacement. From inside the graph knowable: The core of this system is inside place is only of a machine exceed magnetism to send adjustable carry out implement drive power source, odd the set cost that takes key-press through reading comes to a machine call the program that answers relatively, measure the corresponding number that exports electricity changeover of classics D/A converter to be - 5 ～ + the voltage signal of 5V, power enlarge part is its enlarge again - 3 ～ + the voltaic signal of 3A, with making drive coil produces corresponding magnetic field to come drive exceeds magnetism send adjustable material, the displacement that will exceed magnetism to send adjustable material to arise next is delivered through actuator come out. Send the control precision of system of drive of adjustable small displacement to carry excellent magnetism, reduce sluggish to answer etc nonlinear characteristic, the author passes suddenly Er sensor to send the drive magnetic field of adjustable material to undertake monitoring to exceeding magnetism directly, came true to export the closed-loop control of displacement through displacement sensor. Added system of refrigeration of constant temperature water, in order to as a result of,be restrained of drive coil give out heat and cause the heat that exceeds magnetism to send adjustable material stretchy. The small displacement that exceeds magnetism to send adjustable material passes the difficulty that is whole system design and one of focal points with what output force, average transmission deputy small displacement precision is low, and be put in attrition and creeping phenomenon, satisfy the requirement of precision of drive of small displacement of class of rice of micron, accept hard. The circular diaphragm that because this designed a kind of center,thin, circumjacent solid raises thick, margin as this small displacement is carried out implement deliver an orgnaization, this kind of structure is had not only flexible the part of hinge is little, without attrition, without wear away, have a return trip to turn over the advantage such as force without transmission clearance, oneself, still have at the same time flexible the part is stress-free concentration, fatigue when be out of shape intensity it is relatively tall, easy to make wait for a characteristic. This system can use sheet not only piece engine control, still can pass RS-232 serial mouth, implementation and go up a data switch between personal computer and personal computer control. 4 tests result and small feed precision analyse us to exceed magnetism to sent system of drive of adjustable small displacement to undertake the experiment studies to what what develop. The exceeds magnetism to send adjustable club diameter that uses in the experiment is Ø11mm, length is 88mm; Displacement sensor chooses Central Plains to measure the high accuracy inductance that bearing plant produces to measure small appearance; Magnetic field sensor chooses the Huo Er that semiconductor of Chinese Academy of Sciences produces piece; Tesla plan the PG-5 that chooses production of capital Normal University tesla plan. Graph intensity of 3 magnetic induction and displacement curve get on platform of vibration isolation of experimental device park, connect warm-up of constant temperature water above all period of time, connect electric current to send adjustable material to train several times to exceeding magnetism. Next, connect the electric current of successive change, use inductance to measure small appearance to measure magnetism of favorable balance of trade to send the output displacement of system of drive of adjustable small displacement, measure a corresponding magnetic induction intensity through suddenly Er sensor. Graph the relation curve of the 3 output displacement that are a system and magnetic induction intensity. By the graph 3 knowable, output displacement of the system can amount to 40µm. Because this system used magnetic induction intensity to regard control as the quantity, sluggish was reduced to answer coefficient on certain level, raised the repeatability that displacement outputs and control precision. But, when drive magnetic field under 200mT when, displacement output of the system is lesser, and sluggish answers coefficient bigger, when be being used actually accordingly, answer to avoid to use this paragraph of curve as far as possible. The system of small feed closed circuit that we return pair of systems at the same time uses the method that knows constant temperature water the heat the system is stretchy restrain inside very little scope, used displacement sensor to undertake compensating at the same time, because the error of this system is main,by the smallest step pitch of the system of drive of small displacement of sum of errors of sensor two parts are comprised. Synthesize theory according to the error, the small displacement error that is afore-mentioned two errors synthesis the system sends 2+ss2)½(3) form for S=(s in: S is passed -- sensor error Ss -- the S of the smallest step pitch of the system of drive of the smallest step pitch of drive system, it is by the resolution of D/A converter, drive the span of magnetic field is mixed 3 parts decide the biggest slope of the relation curve of output displacement of the system and magnetic induction intensity jointly. The resolution of the D/A converter AD7521 that this system chooses is 12, the span of drive magnetic field is 677.

4mT, and the Kmax of the biggest slope of the relation curve of the system that outputs displacement and magnetic induction intensity but by the graph 3 reach: Kmax=0.

00873µm/T, the smallest step pitch of system of small feed can get Ss=677 by next type.

4Kmax=0.

014µm212-1 to sensor error. Pass can use the sensor with taller precision to undertake to its the experiment determines. Pass actual measurement, the sensor error of this system is more than 0.

1µm. By type (the small displacement error that 3) can get a system is S=(0.

12+0.

0142)½ ≈ 0.

101µm by go up type is knowable, small displacement error of the system basically is caused by the error of sensor, if choose more the displacement sensor of high accuracy, will raise small displacement precision of the system substantially. 5 last words are used exceed magnetism to send adjustable material this kind of new-style function material regards small displacement as parts of an apparatus, development succeeded system of small displacement drive. Through determining actually, output displacement of the system can amount to 40µm, closed-loop control error is more than 0.

101µm, have sluggish to answer Xiaohe to output muscularity, repeatability precision of good, control is advanced advantage. This system can apply at the jiggle feed of cutting tool of accurate machine tool or workbench not only, still can serve as a frequency and amplitude to stimulate Zhen Yuan adjustably to apply at other domain. CNC Milling CNC Machining