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編號
無錫太湖學(xué)院
畢業(yè)設(shè)計(jì)（論文）
相關(guān)資料
題目: 錫柴汽車廠液壓綜合試驗(yàn)臺設(shè)計(jì)
信機(jī) 系 機(jī)械工程及自動化專業(yè)
學(xué) 號： 0923010
學(xué)生姓名： 康 海 成
指導(dǎo)教師： 屠德剛 （職稱：高級工程師 ）
（職稱： ）
2012年5月25日
目 錄
一、畢業(yè)設(shè)計(jì)（論文）開題報(bào)告
二、畢業(yè)設(shè)計(jì)（論文）外文資料翻譯及原文
三、學(xué)生“畢業(yè)論文（論文）計(jì)劃、進(jìn)度、檢查及落實(shí)表”
四、實(shí)習(xí)鑒定表
無錫太湖學(xué)院
畢業(yè)設(shè)計(jì)（論文）
開題報(bào)告
題目： 錫柴汽車廠液壓綜合試驗(yàn)臺設(shè)計(jì)
信機(jī) 系 機(jī)械工程及自動化 專業(yè)
學(xué) 號： 0923010
學(xué)生姓名： 康 海 成
指導(dǎo)教師： 屠德剛 （職稱：高級工程師 ）
（職稱： ）
2011年11月14日
課題來源
本課題是對自卸車上所有液壓元件進(jìn)行綜合試驗(yàn)的裝置，以滿足工廠質(zhì)量控制的要求。由于試驗(yàn)臺已制造完成，并經(jīng)多年使用，故在完善液壓電控原理的基礎(chǔ)上，加以改進(jìn)。
科學(xué)依據(jù)（包括課題的科學(xué)意義；國內(nèi)外研究概況、水平和發(fā)展趨勢；應(yīng)用前景等）
液壓傳動相對機(jī)械傳動來說是一門新技術(shù)，隨著流體力學(xué)、自動控制、計(jì)算機(jī)技術(shù)的不斷發(fā)展，液壓傳動技術(shù)也發(fā)展成為包括傳動、控制、檢測等技術(shù)在內(nèi)的綜合性的機(jī)電液一體化技術(shù)，在工業(yè)生產(chǎn)、設(shè)備控制等各個(gè)方面得到了廣泛的應(yīng)用．在傳統(tǒng)的液壓系統(tǒng)的控制中通常由繼電器等構(gòu)成，但隨著計(jì)算機(jī)技術(shù)、電力電子技術(shù)等的發(fā)展，計(jì)算機(jī)及電子電力控制技術(shù)在液壓傳動控制中也得到了廣泛的應(yīng)用，在西方發(fā)達(dá)國家以計(jì)算機(jī)技術(shù)為核心的PLC技術(shù)已在液壓傳動的控制中也得到了越來越多的應(yīng)用。
液壓實(shí)驗(yàn)臺在液壓產(chǎn)品檢測、液壓系統(tǒng)研究、實(shí)驗(yàn)教學(xué)中有著廣泛的用途，由于這些用途的需要，對液壓實(shí)驗(yàn)臺的組成、控制系統(tǒng)要求有較高的柔性，以適應(yīng)不同的液壓產(chǎn)品、液壓系統(tǒng)或不同的實(shí)驗(yàn)教學(xué)項(xiàng)目要求。
可編程序控制器(PLC)是以微處理機(jī)為基礎(chǔ)，綜合了計(jì)算機(jī)技術(shù)、自動控制技術(shù)和通信技術(shù)等現(xiàn)代科技而發(fā)展起來的一種新型工業(yè)自動控制裝置，是將計(jì)算機(jī)技術(shù)應(yīng)用于T業(yè)控制領(lǐng)域的新產(chǎn)品，具有多輸人／輸出接口，并且具有較強(qiáng)的驅(qū)動能力。
PLC具有可靠性高、抗干擾能力強(qiáng)，靈活性好，編程方便等特點(diǎn)，從而在工業(yè)控制領(lǐng)域得到了廣泛的應(yīng)用。隨著可編程控制器的技術(shù)的發(fā)展，將其代替順序控制器作為液壓實(shí)驗(yàn)臺控制系統(tǒng)的核心，不但能滿足日益復(fù)雜的液壓實(shí)驗(yàn)系統(tǒng)的控制要求，而且作為開發(fā)新的實(shí)驗(yàn)系統(tǒng)提供較大的柔性空間。
研究內(nèi)容
本課題是對現(xiàn)有設(shè)備進(jìn)行測繪，并在改進(jìn)的基礎(chǔ)上制造完成，以滿足實(shí)際使用的要求。在搞清實(shí)驗(yàn)臺工作原理的基礎(chǔ)上，改進(jìn)液壓系統(tǒng)，對于部分電控系統(tǒng)進(jìn)行PLC改裝。在設(shè)計(jì)中對部分結(jié)構(gòu)進(jìn)行有限元分析，包括應(yīng)用UG軟件分析支撐鋼架的應(yīng)力應(yīng)變，用Lingo軟件對油缸中的活塞桿做優(yōu)化設(shè)計(jì)；進(jìn)行三維及二維圖紙的繪制。因設(shè)備已投入使用多年，故在設(shè)計(jì)過程中，可掌握較強(qiáng)的實(shí)際工作經(jīng)驗(yàn)，完成從設(shè)計(jì)到實(shí)際生產(chǎn)及運(yùn)行調(diào)試的整個(gè)過程，這樣一來就能很好的掌握機(jī)電一體化技術(shù)，提高解決實(shí)際工作問題的能力，為以后工作打下極好的基礎(chǔ)。
擬采取的研究方法、技術(shù)路線、實(shí)驗(yàn)方案及可行性分析
文獻(xiàn)索引法,即通過上網(wǎng)和圖書館查找液壓綜合實(shí)驗(yàn)臺的相關(guān)資料。行動研究法，即通過掌握液壓綜合實(shí)驗(yàn)臺的工作原理，結(jié)構(gòu)及其動作流程。了解現(xiàn)有液壓部分的不足并提出解決方法進(jìn)行改進(jìn)，參照其它液壓設(shè)備的PLC電控形式對實(shí)驗(yàn)臺的的部分電控方式進(jìn)行PLC改造。對整臺設(shè)備進(jìn)行改進(jìn)性設(shè)計(jì)和校核，并繪制部分零件圖和設(shè)備的裝備圖以及液壓和電控的原理圖，對必要部件用UG進(jìn)行有限元分析。
研究計(jì)劃及預(yù)期成果
研究計(jì)劃：
2012年10月12日-2012年12月25日：按照任務(wù)書要求查閱論文相關(guān)參考資料，填寫畢業(yè)設(shè)計(jì)開題報(bào)告書。
2013年1月11日-2013年3月5日：填寫畢業(yè)實(shí)習(xí)報(bào)告。
2013年3月8日-2013年3月14日：按照要求修改畢業(yè)設(shè)計(jì)開題報(bào)告。
2013年3月15日-2013年3月21日：學(xué)習(xí)并翻譯一篇與畢業(yè)設(shè)計(jì)相關(guān)的英文材料。
2013年3月22日-2013年4月11日：液壓部分設(shè)計(jì)。
2013年4月12日-2013年4月25日：PLC部分設(shè)計(jì)。
2013年4月26日-2013年5月21日：畢業(yè)論文撰寫和修改工作。
預(yù)期成果：
達(dá)到預(yù)期的實(shí)驗(yàn)結(jié)論：完成了自卸鋼架、液壓缸、液壓原理、電氣原理、總裝等一系列的方案圖形設(shè)計(jì)，實(shí)現(xiàn)了液壓綜合實(shí)驗(yàn)臺的半自動控制。
特色或創(chuàng)新之處
電氣系統(tǒng)部分采用三菱PLC控制，控制電子元件均采用新材料或進(jìn)口名牌元件，經(jīng)久耐用，噪音低，系統(tǒng)的可靠性和可操作性都有所提高。使用UG對自卸油缸的支架進(jìn)行有限元分析。
已具備的條件和尚需解決的問題
本課題是在現(xiàn)有設(shè)備的基礎(chǔ)上進(jìn)行改進(jìn)，是對現(xiàn)有設(shè)備進(jìn)行測繪，并在改進(jìn)的基礎(chǔ)上制造完成，以滿足實(shí)際檢測的要求?，F(xiàn)有設(shè)備的工作原理是知道的。但還有許多不如 人意的地方，如自動控制方面，油缸保壓和防止漏油方面，設(shè)備穩(wěn)定運(yùn)行等方面.本課題就是在現(xiàn)有基礎(chǔ)之上對現(xiàn)有動作進(jìn)行分析，重新設(shè)計(jì)液壓及電控原理圖。
指導(dǎo)教師意見
指導(dǎo)教師簽名：
年 月 日
教研室（學(xué)科組、研究所）意見
教研室主任簽名：
年 月 日
系意見
主管領(lǐng)導(dǎo)簽名：
年 月 日
英文原文
Hydraulic System
Hydraulic presser drive and air pressure drive hydraulic fluid as the transmission is made according to the 17th century, Pascal's principle of hydrostatic pressure to drive the development of an emerging technology, the United Kingdom in 1795 ? Braman Joseph (Joseph Braman ,1749-1814), in London water as a medium to form hydraulic press used in industry, the birth of the world's first hydraulic press. Media work in 1905 will be replaced by oil-water and further improved.
After the World War I (1914-1918) ,because of the extensive application of hydraulic transmission, espec- ially after 1920, more rapid development. Hydraulic components in the late 19th century about the early 20th century, 20 years, only started to enter the formal phase of industrial production. 1925 Vickers (F. Vikers) the invention of the pressure balanced vane pump, hydraulic components for the modern industrial or hydraulic transmission of the gradual establishment of the foundation. The early 20th century G ? Constantimscofluct- uations of the energy carried out by passing theoretical and practical research; in 1910 on the hydraulic trans- mission (hydraulic coupling, hydraulic torque converter, etc.) contributions, so that these two areas of develo- pment.
The Second World War (1941-1945) period, in the United States 30% of machine tool applications in the hydraulic transmission. It should be noted that the development of hydraulic transmission in Japan than Europe and the United States and other countries for nearly 20 years later. Before and after in 1955, the rapid development of Japan's hydraulic drive, set up in 1956, "Hydraulic Industry." Nearly 20 to 30 years, the development of Japan's fast hydraulic transmission, a world leader.
Hydraulic transmission There are many outstanding advantages, it is widely used, such as general industr- ial use of plastics processing machinery, the pressure of machinery, machine tools, etc.; operating machinery engineering machinery, construction machinery, agricultural machinery, automobiles, etc.; iron and steel indu- stry metallurgical machinery, lifting equipment, such as roller adjustment device; civil water projects with flo- od control and dam gate devices, bed lifts installations, bridges and other manipulation of institutions; speed turbine power plant installations, nuclear power plants, etc.; ship from the deck heavy machinery (winch), the bow doors, bulkhead valve, stern thruster, etc.; special antenna technology giant with control devices, measu- rement buoys, movements such as rotating stage; military-industrial control devices used in artillery, ship anti- rolling devices, aircraft simulation, aircraft retractable landing gear and rudder control devices and other devi- ces.
A complete hydraulic system consists of five parts, namely, power components, the implementation of co- mponents, control components, auxiliary components and hydraulic oil.
The role of dynamic components of the original motive fluid into mechanical energy to the pressure that the hydraulic system of pumps, it is to power the entire hydraulic system. The structure of the form of hydra- ulic pump gears are generally pump, vane pump and piston pump.
Implementation of components (such as hydraulic cylinders and hydraulic motors) which is the pressure of the liquid can be converted to mechanical energy to drive the load for a straight line reciprocating movement or rotational movement.
Control components (that is, the various hydraulic valves) in the hydraulic system to control and regulate the pressure of liquid, flow rate and direction. According to the different control functions, hydraulic pressure control valve can be divided into valves, flow control valves and directional control valve. Pressure control valves are divided into benefits flow valve (safety valve), pressure relief valve, sequence valve, pressure relays, etc.; flow control valves including throttle, adjusting the valves, flow diversion valve sets, etc.; directional control valve includes a one-way valve , one-way fluid control valve, shuttle valve, valve and so on. Under the control of different ways, can be divided into the hydraulic valve control switch valve, control valve and set the value of the ratio control valve.
Auxiliary components, including fuel tanks, oil filters, tubing and pipe joints, seals, pressure gauge, oil level, such as oil dollars.
Hydraulic oil in the hydraulic system is the work of the energy transfer medium, there are a variety of mineral oil, emulsion oil hydraulic molding Hop categories.
The role of the hydraulic system is to help humanity work. Mainly by the implementation of components to rotate or pressure into a reciprocating motion.
? Hydraulic system and hydraulic power control signal is composed of two parts, the signal control of some parts of the hydraulic power used to drive the control valve movement.
Part of the hydraulic power means that the circuit diagram used to show the different functions of the interrelationship between components. Containing the source of hydraulic pump, hydraulic motor and auxiliary components; hydraulic control part contains a variety of control valves, used to control the flow of oil, pressure and direction; operative or hydraulic cylinder with hydraulic motors, according to the actual requirements of their choice.
In the analysis and design of the actual task, the general block diagram shows the actual operation of equi - pment. Hollow arrow indicates the signal flow, while the solid arrows that energy flow.
Basic hydraulic circuit of the action sequence - Control components (two four-way valve) and the spring to reset for the implementation of components (double-acting hydraulic cylinder), as well as the extending and retracting the relief valve opened and closed . For the implementation of components and control components, presentations are based on the corresponding circuit diagram symbols, it also introduced ready made circuit diagram symbols.
Working principle of the system, you can turn on all circuits to code. If the first implementation of components numbered 0, the control components associated with the identifier is 1. Out with the implementation of components corresponding to the identifier for the even components, then retracting and implementation of components corresponding to the identifier for the odd components. Hydraulic circuit carried out not only to deal with numbers, but also to deal with the actual device ID, in order to detect system failures.
DIN ISO1219-2 standard definition of the number of component composition, which includes the following four parts: device ID, circuit ID, component ID and component ID. The entire system if only one device, device number may be omitted.
Practice, another way is to code all of the hydraulic system components for numbers at this time, components and component code should be consistent with the list of numbers. This method is particularly applicable to complex hydraulic control system, each control loop are the corresponding number with the system
With mechanical transmission, electrical transmission compared to the hydraulic drive has the following advantages:
1, a variety of hydraulic components, can easily and flexibly to layout.
2, light weight, small size, small inertia, fast response.
3, to facilitate manipulation of control, enabling a wide range of stepless speed regulation (speed range of 2000:1).
4, to achieve overload protection automatically.
5, the general use of mineral oil as a working medium, the relative motion can be self-lubricating surface, long service life;
6, it is easy to achieve linear motion /
7, it is easy to achieve the automation of machines, when the joint control of the use of electro-hydraulic, not only can achieve a higher degree of process automation, and remote control can be achieved.
The shortcomings of the hydraulic system:
1, as a result of the resistance to fluid flow and leakage of the larger, so less efficient. If not handled properly, leakage is not only contaminated sites, but also may cause fire and explosion.
2, vulnerable performance as a result of the impact of temperature change, it would be inappropriate in the high or low temperature conditions.
3, the manufacture of precision hydraulic components require a higher, more expensive and hence the price.
4, due to the leakage of liquid medium and the compressibility and can not be strictly the transmission ratio.
5, hydraulic transmission is not easy to find out the reasons for failure; the use and maintenance requirements for a higher level of technology.
In the hydraulic system and its system, the sealing device to prevent leakage of the work of media within and outside the dust and the intrusion of foreign bodies. Seals played the role of components, namely seals. Medium will result in leakage of waste, pollution and environmental machinery and even give rise to malfunctioning machinery and equipment for personal accident. Leakage within the hydraulic system will cause a sharp drop in volumetric efficiency, amounting to less than the required pressure, can not even work. Micro-invasive system of dust particles, can cause or exacerbate friction hydraulic component wear, and further lead to leakage.
Therefore, seals and sealing device is an important hydraulic equipment components. The reliability of its work and life, is a measure of the hydraulic system an important indicator of good or bad. In addition to the closed space, are the use of seals, so that two adjacent coupling surface of the gap between the need to control the liquid can be sealed following the smallest gap. In the contact seal, pressed into self-seal-style and self-styled self-tight seal (ie, sealed lips) two.
The three hydraulic system diseases
1, as a result of heat transmission medium (hydraulic oil) in the flow velocity in various parts of the existence of different, resulting in the existence of a liquid within the internal friction of liquids and pipelines at the sam- e time there is friction between the inner wall, which are a result of hydraulic the reasons for the oil tempera- ture. Temperature will lead to increased internal and external leakage, reducing its mechanical efficiency. At the same time as a result of high temperature, hydraulic oil expansion will occur, resulting in increased com- pression, so that action can not be very good control of transmission. Solution: heat is the inherent characte -ristics of the hydraulic system, not only to minimize eradication. Use a good quality hydraulic oil, hydraulic piping arrangement should be avoided as far as possible the emergence of bend, the use of high-quality pipe and fittings, hydraulic valves, etc.
2, the vibration of the vibration of the hydraulic system is also one of its malaise. As a result of hydraulic oil in the pipeline flow of high-speed impact and the control valve to open the closure of the impact of the process are the reasons for the vibration system. Strong vibration control action will cause the system to error, the system will also be some of the more sophisticated equipment error, resulting in system failures. Solutions: hydraulic pipe should be fixed to avoid sharp bends. To avoid frequent changes in flow direction, can not avoid damping measures should be doing a good job. The entire hydraulic system should have a good damping measures, while avoiding the external local oscillator on the system.
3, the leakage of the hydraulic system leak into inside and outside the leakage leakage. Leakage refers to the process with the leak occurred in the system, such as hydraulic piston-cylinder on both sides of the leakage, the control valve spool and valve body, such as between the leakage. Although no internal leakage of hydra- ulic fluid loss, but due to leakage, the control of the established movements may be affected until the cause system failures. Outside means the occurrence of leakage in the system and the leakage between the external environment. Direct leakage of hydraulic oil into the environment, in addition to the system will affect the working environment, not enough pressure will cause the system to trigger a fault. Leakage into the enviro- nment of the hydraulic oil was also the danger of fire. Solution: the use of better quality seals to improve the machining accuracy of equipment.
Another: the hydraulic system for the three diseases, it was summed up: "fever, with a father拉稀" (This is the summary of the northeast people). Hydraulic system for the lifts, excavators, pumping station, dynamic, crane, and so on large-scale industry, construction, factories, enterprises, as well as elevators, lifting platforms, Deng Axle industry and so on.
Hydraulic components will be high-performance, high-quality, high reliability, the system sets the direction of development; to the low power, low noise, vibration, without leakage, as well as pollution control, water-based media applications to adapt to environmental requirements, such as the direction of development; the development of highly integrated high power density, intelligence, mechatronics and micro-light mini-hydraulic components; active use of new techniques, new materials and electronics, sensing and other high-tech.
---- Hydraulic coupling to high-speed high-power and integrated development of hydraulic transmission equ- ipment, development of water hydraulic coupling medium speed and the field of automotive applications to develop hydraulic reducer, improve product reliability and working hours MTBF; hydraulic torque converter to the development of high-power products, parts and components to improve the manufacturing process tech -nology to improve reliability, promote computer-aided technology, the development of hydraulic torque con- verter and power shift transmission technology supporting the use of ; Clutch fluid viscosity should increase the quality of products, the formation of bulk to the high-power and high-speed direction.
Pneumatic Industry:
---- Products to small size, light weight, low power consumption, integrated portfolio of development, the implementation of the various types of components, compact structure, high positioning accuracy of the direction of development; pneumatic components and electronic technology, to the intelligent direction of development; component performance to high-speed, high-frequency, high-response, high-life, high temp- erature, high voltage direction, commonly used oil-free lubrication, application of new technology, new technology and new materials.
(1) used high-pressure hydraulic components and the pressure of continuous work to reach 40Mpa, the maximum pressure to achieve instant 48Mpa;
(2) diversification of regulation and control;
(3) to further improve the regulation performance, increase the efficiency of the powertrain;
(4) development and mechanical, hydraulic, power transmission of the composite portfolio adjustment gear;
(5) development of energy saving, energy efficient system function;
(6) to further reduce the noise;
(7) Application of Hydraulic Cartridge Valves thread technology, compact structure, to reduce the oil spill.
中文譯文
液壓系統(tǒng)
液壓傳動和氣壓傳動稱為流體傳動，是根據(jù)17世紀(jì)帕斯卡提出的液體靜壓力傳動原理而發(fā)展起來的一門新興技術(shù)，1795年英國約瑟夫?布拉曼(Joseph Braman,1749-1814)，在倫敦用水作為工作介質(zhì)，以水壓機(jī)的形式將其應(yīng)用于工業(yè)上，誕生了世界上第一臺水壓機(jī)。1905年將工作介質(zhì)水改為油，又進(jìn)一步得到改善。
第一次世界大戰(zhàn)(1914-1918)后液壓傳動廣泛應(yīng)用，特別是1920年以后，發(fā)展更為迅速。液壓元件大約在 19 世紀(jì)末 20 世紀(jì)初的20年間，才開始進(jìn)入正規(guī)的工業(yè)生產(chǎn)階段。1925 年維克斯(F.Vikers)發(fā)明了壓力平衡式葉片泵,為近代液壓元件工業(yè)或液壓傳動的逐步建立奠定了基礎(chǔ)。20 世紀(jì)初康斯坦丁?尼斯克對能量波動傳遞所進(jìn)行的理論及實(shí)際研究;1910年對液力傳動(液力聯(lián)軸節(jié)、液力變矩器等)方面的貢獻(xiàn)，使這兩方面領(lǐng)域得到了發(fā)展。
第二次世界大戰(zhàn)(1941-1945)期間,在美國機(jī)床中有30%應(yīng)用了液壓傳動。應(yīng)該指出,日本液壓傳動的發(fā)展較歐美等國家晚了近 20 多年。在 1955 年前后 , 日本迅速發(fā)展液壓傳動,1956 年成立了“液壓工業(yè)會”。近20~30 年間，日本液壓傳動發(fā)展之快，居世界領(lǐng)先地位。
液壓傳動有許多突出的優(yōu)點(diǎn)，因此它的應(yīng)用非常廣泛，如一般工業(yè)用的塑料加工機(jī)械、壓力機(jī)械、機(jī)床等；行走機(jī)械中的工程機(jī)械、建筑機(jī)械、農(nóng)業(yè)機(jī)械、汽車等；鋼鐵工業(yè)用的冶金機(jī)械、提升裝置、軋輥調(diào)整裝置等；土木水利工程用的防洪閘門及堤壩裝置、河床升降裝置、橋梁操縱機(jī)構(gòu)等；發(fā)電廠渦輪機(jī)調(diào)速裝置、核發(fā)電廠等等；船舶用的甲板起重機(jī)械（絞車）、船頭門、艙壁閥、船尾推進(jìn)器等；特殊技術(shù)用的巨型天線控制裝置、測量浮標(biāo)、升降旋轉(zhuǎn)舞臺等；軍事工業(yè)用的火炮操縱裝置、船舶減搖裝置、飛行器仿真、飛機(jī)起落架的收放裝置和方向舵控制裝置等。
一個(gè)完整的液壓系統(tǒng)由五個(gè)部分組成，即動力元件、執(zhí)行元件、控制元件、輔助元件和液壓油。
動力元件的作用是將原動機(jī)的機(jī)械能轉(zhuǎn)換成液體的壓力能，指液壓系統(tǒng)中的油泵，它向整個(gè)液壓系統(tǒng)提供動力。液壓泵的結(jié)構(gòu)形式一般有齒輪泵、葉片泵和柱塞泵。
執(zhí)行元件(如液壓缸和液壓馬達(dá))的作用是將液體的壓力能轉(zhuǎn)換為機(jī)械能，驅(qū)動負(fù)載作直線往復(fù)運(yùn)動或回轉(zhuǎn)運(yùn)動。
控制元件(即各種液壓閥)在液壓系統(tǒng)中控制和調(diào)節(jié)液體的壓力、流量和方向。根據(jù)控制功能的不同，液壓閥可分為壓力控制閥、流量控制閥和方向控制閥。壓力控制閥又分為益流閥(安全閥)、減壓閥、順序閥、壓力繼電器等；流量控制閥包括節(jié)流閥、調(diào)整閥、分流集流閥等；方向控制閥包括單向閥、液控單向閥、梭閥、換向閥等。根據(jù)控制方式不同，液壓閥可分為開關(guān)式控制閥、定值控制閥和比例控制閥。
輔助元件包括油箱、濾油器、油管及管接頭、密封圈、壓力表、油位油溫計(jì)等。
液壓油是液壓系統(tǒng)中傳遞能量的工作介質(zhì)，有各種礦物油、乳化液和合成型液壓油等幾大類。
液壓系統(tǒng)的作用就是幫助人類做工。主要是由執(zhí)行元件把壓力變成轉(zhuǎn)動或往復(fù)運(yùn)動。
液壓系統(tǒng)由信號控制和液壓動力兩部分組成，信號控制部分用于驅(qū)動液壓動力部分中的控制閥動作。
液壓動力部分采用回路圖方式表示，以表明不同功能元件之間的相互關(guān)系。液壓源含有液壓泵、電動機(jī)和液壓輔助元件；液壓控制部分含有各種控制閥，其用于控制工作油液的流量、壓力和方向；執(zhí)行部分含有液壓缸或液壓馬達(dá)，其可按實(shí)際要求來選擇。
在分析和設(shè)計(jì)實(shí)際任務(wù)時(shí)，一般采用方框圖顯示設(shè)備中實(shí)際運(yùn)行狀況。 空心箭頭表示信號流，而實(shí)心箭頭則表示能量流。
基本液壓回路中的動作順序—控制元件（二位四通換向閥）的換向和彈簧復(fù)位、執(zhí)行元件（雙作用液壓缸）的伸出和回縮以及溢流閥的開啟和關(guān)閉。 對于執(zhí)行元件和控制元件，演示文稿都是基于相應(yīng)回路圖符號，這也為介紹回路圖符號作了準(zhǔn)備。
根據(jù)系統(tǒng)工作原理，您可對所有回路依次進(jìn)行編號。如果第一個(gè)執(zhí)行元件編號為0，則與其相關(guān)的控制元件標(biāo)識符則為1。如果與執(zhí)行元件伸出相對應(yīng)的元件標(biāo)識符為偶數(shù)，則與執(zhí)行元件回縮相對應(yīng)的元件標(biāo)識符則為奇數(shù)。 不僅應(yīng)對液壓回路進(jìn)行編號，也應(yīng)對實(shí)際設(shè)備進(jìn)行編號，以便發(fā)現(xiàn)系統(tǒng)故障。
DIN ISO1219-2標(biāo)準(zhǔn)定義了元件