Summary: Use certain crystal data go against what the character that suppress report makes with modern production technology to press electric actuator (report, ) of mechanical displacement converter, can have the characteristic that answers small-sizedly, puissantly, high. The article as a child model, tall the angle that answers hydraulic pressure to dominate a powerful person or family, the character that presses electric actuator to pressing electric data to reach and the applied current situation that go up in a powerful person of hydraulic pressure control make one simple introduction. Keyword: Press electric actuator hydraulic pressure to dominate a powerful person or family tall the response that answers hydraulic pressure servo function basically depends on the response that dominates a powerful person or family speed. The response that raises control a powerful person or family is the objective that people pursues hard all the time. In recent years, the piezoelectric effect that abroad uses certain crystal data will develop tall answer electro-hydraulic a powerful person, gain a few headway. The article makes some of introduction with respect to this respect circumstance. 1 press electric actuator (the characteristic material suppressing report of data of 1) pressing report is material of a kind of crystal. Its characteristic is to become when its get outside force and generation is out of shape, can be in as a result of in-house polarization apparently generation charge, daily gas burner portfire used this principle namely. Conversely, if be in,the electric field of particular strength brings to bear on on the polarization direction of the material that suppress report, the machinery that can cause material is out of shape. Virgin state can reinstate again after take out electric field. Type of the drive that suppress report is electro-hydraulic this character that a powerful person used the data that suppress report namely (call electrostriction effect or go against piezoelectric effect) . Use at making electro-hydraulic the data suppressing report that dominates a powerful person or family can divide it is two kinds big: One kind is the pottery and porcelain that suppress report, among them with PZT(Pb(Zr, ti)Q3) series is most common, the characteristic is conductivity low, it is good to allow working temperature condition (120 ～ of ＜ 200 ℃ ) , the high speed that often is used at digital a powerful person leaves, involve drive; Another kind is voltage changes material, commonner be like PMN(Pb(Mg, nb)O3) , its characteristic is material is out of shape 2 times when get tension with place just become scale, and sluggish annulus is lesser, use at drive of the scale of pilot valve, servo. (2) presses the structure of electric actuator to press the meet an emergency of electric data to be controlled for 10-3 commonly. Accordingly, if use the strain of a piezocrystal that is 20mm high directly, its are out of shape it is 20 μ M only, for the displacement of core of a powerful person that asks at place of a powerful person of real hydraulic pressure relatively too small. Accordingly, need to magnify its meet an emergency, often adopt a few kinds of following measure at present. ① is multilayer chip. The meet an emergency that if use the chip with larger monolayer to produce place,needs (be out of shape) , be in the requirement chip is polar bring to bear on very tall voltage (like 1000V above) . And multilayer chip it is will individual chip is done very thinly, next each increase tension respectively, final overlay rises. If the graph is shown 1 times, can use lesser tension so (it is commonly under 150V) obtain bigger overlay to be out of shape. Graph 1 multilayer chip press ② of electric actuator double chip. Double chip basic structure is two length direction adjustable metabolic controls electric chip stickup in together on flexibility board, after electrify is pressed, two chip together stretchy, another shortens, cause whole thereby bend (2) seeing a picture. It is easier that this kind of type is made, change expand rate is higher also (change can amount to hundreds μ M) , it is a kind of more commonly used type. Because use,defect is is to bend be out of shape, answer speed slower, the power of generation is not great also. Graph 2 pairs of chip control lever of ③ of electric actuator enlarge. This is a kind of the simplest and original plan. If the graph is shown 3 times, its principle is to pass a lever general of one piezocrystal be out of shape give enlarge. Of course, because lever fulcrum metabolic is affected, the displacement of lever end points won't be so as big as what look. On the other hand, using piezocrystal to make fluid dominate an end of a powerful person is bulk miniaturization, and lever enlarge apparent meeting brings about structural dimension big, it is an adverse element. Other still has a few to be out of shape enlarge method, because application is less, the article did not grant to be listed one by one. Graph 3 lever enlarge press electric actuator to use the data that suppress report a few times 2 development is tall the research example that answers fluid to charge a powerful person (what 1) uses the double chip data that suppress report is tall answer graph of servo a powerful person 4 use PMN macle for a kind. In this a powerful person, nozzle fender itself is the double chip material that suppress report, the voltage that differs through bringing to bear on to its and generation is out of shape accordingly, controlled pilot valve is core of common a powerful person of servo a powerful person. In addition, the plate washer in this a powerful person connects with pilot valve photograph no longer and have feedback bedspring effect, set displacement sensor additionally on a powerful person to undertake feedback however. According to the report [1] , undertake controlling to the pilot valve of diameter of a 4mm, the frequency noise of a powerful person can amount to 1kHz above. 1, of plate washer of the double chip material that suppress report 2, nozzle mouth 3, pilot valve? 4, of mouth of fixed reduce expenditure 5, sensor of pilot valve position pursues 4 those who use the double chip data that suppress report is tall answer of servo a powerful person (Gu Wu university uses the name of Japan of a powerful person of high speed switch that 2) uses the double chip data that suppress report PZT pair, developed a kind to answer frequency to shed a powerful person or family of high speed switch with larger amount higher, graph 5 for its working principle pursues [2] . If plan institute is shown, the nozzle that this a powerful person differs through controlling a double chip material that suppress report to plate washer will shut or be opened with drive an awl a powerful person moves. Actual result makes clear, this a powerful person answers frequency to be able to amount to 200Hz, when 20MPa system oil pressure output discharge is amounted to 9. 24L/min. Its are the biggest answer frequency to be the same as norms a powerful person or family of electromagnetism of switch of common high speed is the 2 times what answer frequency biggest. Pursue the of 5 a powerful person of high speed switch that use the double chip data that suppress report (3) is multilayer chip + the high speed of orgnaization of lever type enlarge answers the servo a powerful person that graph of servo a powerful person shows 6 times two end of core part as multilayer as PMN chip + lever type magnifies, two groups of actuating device are pushed pull drive the core of a powerful person of 5mm of a diameter moves. Positional sensor is set to detect in a powerful person speed of motion of core of a powerful person, in feedbacking this signal to control a system, to core of a powerful person motion undertakes controlling, the frequency noise of a powerful person can be amounted to 1.
3kHz. Graph 6 multilayer chip + the high speed of lever enlarge orgnaization answers of servo a powerful person (4) is used directly multilayer the freeboard of chip fast switch a powerful person pursues 7 in, use two groups multilayer data of chip pressing report drives core of a powerful person of an awl a powerful person, form 2 3 numbers (switch a powerful person) [3] . Multilayer to only group chip, bring to bear on when 100V voltage, falling without laden circumstance, can produce displacement of 15 μ M, impetus 850N. This is medium, the diameter of core of a powerful person of awl a powerful person is 20.
2mm, press press area 2.
5 × 10-4m2, quality 0.
012kg. Example makes clear, below drive of voltage of 0 ～ 100V, the add up to of switch switch time of a powerful person does not exceed 70 μ S. Can dog the square wave signal of 2kHz (the switch switch time of a powerful person of switch of common high speed is controlled for 50ms, can dog the) of square wave signal that 100Hz controls. Document [3] in, still such two freeboards fast switch a powerful person controls glance a powerful person to make valve of servo of type of a number, pilot valve quality 0.
009kg, press press area 5 × 10-5 M2, the square wave that can track 890Hz when systematic pressure 170MPa (pilot valve journey is in 0.
5 ～ 1mm) , can obtain larger flow. Graph 7 use multilayer the freeboard of chip drive fast switch a powerful person the people understanding to piezoelectric effect and application already had 3 last words quite long history. Piezocrystal element is had answer the characteristic with rapid rate. Accumulate stratification as the rise and brings chip of production technology in recent years especially (multilayer chip) successful, make pressed electric actuator to have but low voltage drive, bulk the small, good point that drives muscularity. Change to be being answered the miniaturization of the control a powerful person in domain of hydraulic pressure technology, high wait for the function with will have particular. CNC Milling