【正文】 of front blunt certainly repress a see, in the system study, from adjust to carry on the back entrance pressure of press the valve and be subjected to an oil urn two chambers hydraulicpneumatic prehensive load a disappeared moment, from adjust to carry on the back the pressure of press the valve quickly rises, and stabilize the number which starts to carry on the back to press at the beginning in the Gao the diagram it is thus clear that, from adjust to carry on the back to press to adjust soon the system is in a twinkling load to disappear oil urn carry the range that the pressure go up on oil urn39。t big, oil urn two chamber pressures also more and greatly didn39。s carry on a reasonable design, the dynamic state characteristic canmake to slip a pedestal is shown Zhao ground an explained adoption power in make to slip a pedestal is shown Zhao ground an explained adoption power inplications not line is convenience valid of. In 1946 the first electronic accounting machine was born in the world, thisindicated the humanity created has been possible to strengthen and partially toreplace the mental labor the tool. It with the humanity these which in the agriculture, the industry society created only is strengthens the physical labor the tool to pare, got up the quantitive leap, entered the information society for the humanity to lay the foundation. After 6 years, in 1952, puter technology applied to the engine bed , the first numerical control engine bed were born in US. From this time on, thetraditional enginebed hashad the archery target change. Since nearly half century, the numerical control system has experienced two stages and six generation of development. The early puter operating speed is low, was not big to then science putation and the data processing influence, but could not adapt the engine bed realtime control request. The people can not but use numeral logic circuit to build to bee an engine bed special purpose puter to take the numerical control system, is called the hardware connection numerical control (HARDWIREDNC), Jian Chengwei numerical control (NC). 6 Along with the primary devicedevelopment, this stage has had been through repeatedly three generations, namely 1952first generation of electron tube。s experience, the processing general rule and the special rule store in the system, take the craft parameter database as the strut, the establishment has the artificial intelligence the expert system. introduces the breakdown to diagnose the expert system intellectualized numeral servo drive May through the automatic diagnosis load, but the automatic control parameter, causes the actuation system to obtain the best movement. Second, engine bed numerical control transformation necessity From on microscopic looked below that, the numerical control engine bed has the prominent superiority pared to the traditional engine bed, moreover these superiority e from the puter might which the numerical control system contains. may process the traditional engine bed cannot process the curve, the curvedsurface and so on the plex ponents. Because the puter has the excellent operation ability, may the instant accurately calculate each coordinate axis instant to be supposed the movement physiological load of exercise, therefore may turn round the synthesis plex curve or the curved surface. may realize the processing automation, moreover is the flexible automation, thus the efficiency may enhance 3 ~ 7 times pared to the traditional engine bed. Because the puter has the memory and the memory property, may the procedure which inputs remember and save, then the order which stipulated according to the procedure automatic carries out, thus realization automation. The numerical control engine bed so long as replaces a procedure, may realize another work piece processing automation, thus causes the single unit and the small batch of production can automate, therefore is called has realized flexible automation. From on macroscopic looked that, the industry developed country armed forces, the airplane weapon industry, in the end of the 7039。 Third is renovates, for increases the precision, the efficiency and theautomaticity, to the machinery, the electricity partially carries on renovates, reassembles the processing to themachine part, extensively recovers the precision。通過計(jì)算機(jī)數(shù)字仿真，分析了滑臺(tái)產(chǎn)生前沖和運(yùn)動(dòng)不平穩(wěn)的原 及主要影響 素?；_(tái)上負(fù)載的突然消失引起的前沖以及負(fù)載的周期變化引起的運(yùn)動(dòng)不平穩(wěn)，都將影響被加工件的表面質(zhì)量，嚴(yán)重時(shí)會(huì)致使刀具折斷。 2動(dòng)態(tài)數(shù)學(xué)模型 組合機(jī)床滑臺(tái)的液壓驅(qū)動(dòng)系統(tǒng)一自調(diào)背壓調(diào)速系統(tǒng)的工作原理圖如圖 I所示。對(duì)象該系統(tǒng)這樣的復(fù)雜非線性系統(tǒng)，為了便于研究其動(dòng)態(tài)特性，建立一個(gè)僅著重考慮主要影響因素的合理簡(jiǎn)單的動(dòng)態(tài)數(shù)學(xué)模型是尤其重要的 [1][2]。本論文中所使用的符號(hào)： s1流源，即調(diào)速閥出口流量； Sel— 滑臺(tái)滑動(dòng)摩擦力 R 一滑臺(tái)等效粘性摩擦系數(shù) I1— 滑臺(tái)與油缸的質(zhì)量 12— 自調(diào)背壓閥閥心質(zhì)量 C c2— 油缸無桿腔及有桿腔的液容 11 C2— 自調(diào)背壓閥彈簧柔度 R1, R2 自調(diào)背壓閥阻尼孔液阻， R9— 自調(diào)背壓閥閥口液阻 Se2— 自調(diào)背壓閥彈簧的初始預(yù)緊力； I4, I5— 管路的等效液感 C C6— 管路的等效液容： R5, R7管路的等效液阻； V3, V4— 油缸無桿腔及有桿腔內(nèi)容積； P3, P4— 油缸無桿腔及有桿腔的壓力 F— 滑臺(tái)承受負(fù)載， 滑臺(tái)前沖現(xiàn)象是作用在滑臺(tái)上的負(fù)載突然消失（如鉆透工作情況 )引起的。然而，滑臺(tái)的前沖使油缸有桿腔油液受壓引起背壓升高，從而消耗掉系統(tǒng)中的一部分能量，對(duì)滑臺(tái)的前沖起一定的抑制作用?？梢姴捎米哉{(diào)背莊調(diào)速系統(tǒng)作為驅(qū)動(dòng)系統(tǒng)的滑臺(tái)在抑制前沖方面具有良好的特性，其中自調(diào)背壓閥起了很大作用。由此可見該系統(tǒng)與傳統(tǒng)的調(diào)速系統(tǒng)有著相同的變化規(guī)律和非常接近的數(shù)值。從系統(tǒng)的結(jié)構(gòu)得知，油缸有桿腔與排油管間有一很大的容積，如圖 6a 所示。 通過理論分析和計(jì)算機(jī)仿真研究 ,自調(diào)背壓調(diào)速系統(tǒng)作為組合機(jī)床滑臺(tái)的驅(qū)動(dòng)系統(tǒng)是很有推廣使用價(jià)值的。 1946 年誕生了世界上第一臺(tái)電子計(jì) 機(jī)，這表明人類創(chuàng)造了可增強(qiáng)和部分代替腦力勞動(dòng)的工具。近半個(gè)世紀(jì)以來，數(shù)控系統(tǒng)經(jīng) 歷了兩個(gè)階段和六代的發(fā)展。 到 1970 年，通用小型計(jì) 機(jī)業(yè)已出現(xiàn)并成批生產(chǎn)。這是因?yàn)樾⌒陀?jì) 機(jī)功能太強(qiáng)，控制一臺(tái)機(jī)床能力有富裕（故當(dāng)時(shí)曾用于控制多臺(tái)機(jī)床，稱之為群控），不如采用微處理器經(jīng)濟(jì)合理。 到了 1990 年， PC 機(jī)的性能已發(fā)展到很高的階段，可以滿 作為數(shù)控系統(tǒng)核心部件的要求。 基于 PC 所具有的開放性、低成本、高可靠性、軟硬件資源豐富等特點(diǎn)，更多的數(shù)控系統(tǒng)生產(chǎn)廠家會(huì)走上這條道路。 隨著人工智能在計(jì) 機(jī)領(lǐng)域的不斷滲透和發(fā)展，數(shù)控系統(tǒng)的智能化程度將不斷提高。 從微觀上看，數(shù)控機(jī)床比傳統(tǒng)機(jī)床有以下突出的優(yōu)越性，而且這些優(yōu)越性均來自數(shù)控系統(tǒng)所包含的計(jì)算機(jī)的威力。 由于計(jì) 機(jī)有記憶和存儲(chǔ)能力，可以將輸入的程序記住和存儲(chǔ)下來，然后按程序規(guī)定的順序自動(dòng) 去執(zhí)行，從而實(shí)現(xiàn)自動(dòng)化。擁有自動(dòng)報(bào)警、自動(dòng)監(jiān)控、自動(dòng)補(bǔ)償?shù)榷喾N自律功能，因而可實(shí)現(xiàn)長時(shí)間無 看管加工。數(shù)控技術(shù)已經(jīng)成為制造業(yè)自動(dòng)化的核心技術(shù)和基礎(chǔ)技術(shù)。以及在其生產(chǎn)的產(chǎn)品中增加信息技術(shù)，包括人工智能等的含量。在美國、日本、德國，用數(shù)控技術(shù)改造機(jī)床和生產(chǎn)線具有廣闊的市場(chǎng)，已形成了機(jī)床和生產(chǎn)線數(shù)控改造的新的行業(yè)。從事改裝業(yè)的著名公司有：大隈工程集團(tuán)、崗三機(jī)械公司、千代田工機(jī)公司、野崎工程公司、濱田工程公司、山本工程公司等。一般大型機(jī)床改造，只花新機(jī)床購置費(fèi)用的 1/3，交貨期短。