外文翻譯--關(guān)于液壓挖掘機(jī)

1、<p><b>　　附錄</b></p><p>　　About hydraulic excavator</p><p>　　The hydraulic excavator plays a great role as representatives of engineering machinery products in the social constru

2、ction, which is widely used in the working strength, the construction quality and improved labor productivity having a very significant role, especially fully hydraulic excavator. It is the key factor that excavator work

3、ing device’ performance decide to work efficiency. Its design directly determines the level of performance of the excavator. The machine is a typical work device a</p><p>　　Hydraulic system and power system

4、are the most important hydraulic excavator, its core system is the biggest in the cost of the proportion. Hydraulic system is as a transmission and energy distribution system to determine the driver most of the operating

5、 experience directly. Currently mainly focuse on industry in hydraulic system in several aspects of the role in excavators:</p><p>　　(1) the handling characteristics and flow distribution;</p><p&g

6、t;　　(2) saving energy； </p><p>　　(3) the energy density and reliability.</p><p>　　A complete hydraulic system consists of five parts, namely, power components, the implementation of components,

7、control components, auxiliary components (Annex) and the hydraulic oil.The role of dynamic components is the original motivation of the mechanical energy into fluid pressure energy, the hydraulic system of pumps, which p

8、rovide power to the entire hydraulic system. Structure of hydraulic pumps generally have gear pumps, vane pumps and piston pumps.Implementation of components (such as h</p><p>　　The quality of a hydraulic sy

9、stem depends not only on the rational design and performance of the merits of system components, but also because of the pollution prevention and treatment system, the system of pollution directly affects the reliability

10、 of hydraulic systems and components of work life, according to Statistics, the hydraulic system failure at home and abroad about 70% were due to pollution caused.</p><p>　　Oil pollution damage following mai

11、n elements of the system：</p><p>　　1) The components of the pollution of wear and tear，Oil components of various pollutants cause various forms of wear, the solid particles into motion pair gap, cutting the

12、part surface wear or fatigue wear. High-speed flow of solid particles on the surface of components caused by the impact of erosion. Oil in the water and the resultant deterioration of oil oxidation corrosion of the compo

13、nents produced. In addition, the system's oil in the air caused cavitation, resulting in surface erosion and</p><p>　　2) Block and the clamping device failure，Solid particles plug the gap and the hydraul

14、ic valve orifice, causing obstruction and clamping the spool and affect performance, or even result in serious accidents.</p><p>　　3) To accelerate the deterioration of oil properties，Oil in the water and ai

15、r for its thermal oxidation of the main conditions is the oil, and oil in the oxidation of metal particles on the oil play an important catalytic role, in addition, the oil bubbles in the water and suspended deputy campa

16、ign significantly reduced Between the film's strength, the lubrication performance.</p><p>　　Before a system is put into the general to go through the wash, rinse aim is to remove residual contaminants i

17、n the system, metal scrap, fiber compounds, core, etc., in the first two hours of work, even if not completely corrupt system, also Cause a series of failures. Therefore, the following steps should be oil cleaning system

18、：</p><p>　　1) With a easy to clean dry cleaning solvent tank, and then filtered clean air solvent residue；</p><p>　　2) All pipe cleaning system, in some cases need to be impregnated pipe and fit

19、tings；</p><p>　　3) Are installed with the oil filter in the pipeline to protect the oil pipeline valves and pressure lines；</p><p>　　4) Set a wash coat converter board to replace the precision v

20、alves, such as electro-hydraulic servo valve；</p><p>　　5) Check all piping size is appropriate, the connection is correct.</p><p>　　If the system used hydraulic servo valve, I might say a few wo

21、rds, the servo valve was washed plate to make the flow of oil from the oil pipeline set of converters, and direct return to tank, so that oil can flow again to Flushing system, so that the oil filter to filter out solid

22、particles, washing process, not every 1 to 2 hours to check the oil filter, oil filter to prevent clogging by contaminants, do not open the bypass at this time, if the starting block to find the oil filter Filter oil c&l

23、t;/p><p>　　Planned maintenance: Regular maintenance of the system create a system for better maintenance of the hydraulic system following recommendations:</p><p>　　1) up to 500 hours or three mont

24、hs will check and replace fluids.</p><p>　　2) Regular washing of the imported oil filter pump.</p><p>　　3) Check the hydraulic oil or other pollutants by acidification of the situation, the smel

25、l of hydraulic oil can generally identify whether the deterioration.</p><p>　　4) Repair leak in your system</p><p>　　5) ensure that no foreign particles from the fuel tank breather cap, oil filt

26、er in the plug seat, return line gasket, and other openings into the fuel tank fuel tank.</p><p>　　Leakage of the hydraulic system and control of hazards:</p><p>　　First, the reasons for the lea

27、kage of hydraulic system:</p><p>　　(1) design and manufacturing defects caused by;</p><p>　　(2) shock and vibration caused by loose fittings;</p><p>　　(3) dynamic seals and wear eac

28、h other with the pieces (particularly the hydraulic cylinder);</p><p>　　(4) high oil and rubber seal deterioration and hydraulic oil incompatibility. The following combination of the above aspects to look at

29、 the control of leakage measures.</p><p>　　Second, control the leakage of the hydraulic system control scheme.</p><p>　　Choice of hydraulic components outside the package leak in the hydraulic s

30、ystem often plays a decisive impact. This determines our technical staff in the new product design, improvement of old products, to tanks, pumps, valves, seals, hydraulic accessories such as the choice of selecting the b

31、est to the spirit of good, excellent choice of cheaper prudent principle, A comparison to.</p><p>　　In the rigid static seals to prevent oil leakage between the fixed surface. Rational design of sealing groo

32、ve dimensions and tolerances, so that after installation of the seal to be squeezed in order to stuff with the deformation microstructure of the surface depression, and to seal the internal stress increased to higher tha

33、n the pressure to be sealed. When the part stiffness is not big enough or when the bolt preload, with the surface under pressure in the separation of oil, causing the sealin</p><p>　　Premature seal deteriora

34、tion may be caused by many factors, one important factor is the oil temperature is too high. 10 ℃ the temperature increases seal life will be halved, it should be rational and efficient design of hydraulic systems or coo

35、ling device, the optimal oil temperature is kept below 65 ℃; construction machinery should never exceed 80 ℃; another factor May be used in oil and sealing material compatibility issues, should be selected using the manu

36、al or the manual hydraulic oil and s</p><p>　　The handling characteristics and flow distribution are a couple of mutual influence factors. In the pilot fluid control condition, each of the flow of oil indepe

37、ndence and control properties effect each other. There are often general requirement liquid pilot handle with corresponding intuitive feelings or motor oil cylinder, which is the movement of linear relationship, such o

38、perator is very easy to use. On the other hand, a set of system in the implementation of the number are greater than th</p><p>　　Current excavator hydraulic system is to adjust the main idea of the energy fl

39、ow of the pump as close to load demand so that it is not too many overflow loss. Typically using load pressure changes feedback to adjust the variable pump as the angle of inclining dish of pump flow control output. For

40、pump from the mouth P actuator used should be loads of feedback control oil pump pressure position for energy saving system also has effect on the performance of common load sensor system, is directly</p><p&g

41、t;　　Pump outlet pressure control, the system of the inclined plate is very close to pump pressure feedback from the feedback loop may be made with the pump of), make speed throttling loss of pressure difference is small,

42、 micro train P good performance. Another kind of power control feedback control valve, pressure from from actuators, represented by Japanese manufacturer of negative flow system is using this form, its advantage is mainl

43、y to the load quicker response, but because the feedback from th</p><p>　　Facing the increasingly high power demand, due to the large flow will lead to loss of volume increased and the system, hydraulic driv

44、ing system is to choose to flow direction development, high demanding by multiple pump parallel to solve, foreign advanced excavator hydraulic components in about 30 MPa pressure rating for the seal, and the cleanness oi

45、l and put forward higher request. In reliability, through theoretical and experimental method is mainly for pump, valve with high in the face with </p><p>　　As the hydraulic technology, the 20th century, 40

46、years on a tractor equipped with hydraulic suspension-type backhoe excavators, `the 20th century, the early and mid 50's have developed a towed the entire rotation hydraulic excavators and crawler hydraulic mining Ma

47、chine, the initial prototype of the hydraulic excavator is the use of aircraft and machine tools hydraulic technology, the lack of a variety of working conditions for the hydraulic excavator components, manufacturing qua

48、lity is not st</p><p>　　Industrial production in developed countries earlier excavators, France, Germany, the United States, Russia, Japan, is a bucket capacity of 3.5-40 m3 hydraulic excavator of the major

49、producing countries, 80 from the 20th century, began production of large excavators. For example, U.S. Shawn Marion produced spin-off of 50-150 m3 capacity bucket excavator, bucket capacity of 132 m3 of Walking Dragline

50、excavators; BE produced the bucket capacity of 168.2 m3 of pedestrian Dragline excavator, bucket</p><p>　　From the late 20th century, the international production to large-scale excavators, miniaturization,

51、 multi-functional, special and automation direction.</p><p>　　1) The development of multi-species, multi-functional, high quality and efficient excavators. To meet the municipal construction and agricultural

52、 construction, the overseas development of the capacity of 0.25 m3 bucket below the mini-excavator, bucket capacity of the smallest is only 0.01 m3.</p><p>　　2) the rapid development of hydraulic excavators,

53、 continuous improvement and innovation in control, so that excavators from simple manipulation of the development to the hydraulic control lever, pneumatic control, hydraulic servo control and electrical control, radio r

54、emote control, computer integrated process control.</p><p>　　3) to adopt new technologies, new processes, new structure, speed up the standardization, serialization, universal growth. For example, the German

55、 company Atlas excavators fitted with a new type of engine speed control device, the excavator of its operational requirements at the most appropriate speed to work; a Belt Lincoln's new LS-5800 C Series Hydraulic mi

56、ning installation of the automatic control hydraulic system, can automatically adjust the flow, avoiding the waste of drive power. Also in</p><p>　　4) Update design theory, improve reliability, extend servic

57、e life. United States, Britain, Japan and other countries promote the use of finite life design theory as an alternative to the traditional design theory and methods of infinite life, and fatigue damage accumulation theo

58、ry, fracture mechanics, finite element method, optimal design, computer-controlled electro-hydraulic servo fatigue Test technique, fatigue strength analysis of hydraulic excavators and other advanced technology in the in

59、t</p><p>　　5) to strengthen labor protection for the driver to improve driver working conditions. Hydraulic excavator with a falling object protective structure and the cab rollover protection structure, the

60、 flexibility of installing adjustable seat, with sound measures to reduce noise interference.</p><p>　　Domestic small dig hydraulic components matching purchase goal mainly is the overseas well-known brand p

61、roduct. This situation is the main reason of the hydraulic system in domestic and abroad in performance, reliability, causing a lot of products between the domestic market of domestic element lack of recognition. At pres

62、ent domestic excavator hydraulic system with foreign enterprises is still at the industry, imitate the stages of learning.</p><p>　　The functions, types and the excavator working features:</p><p&g

63、t;　　Single excavator and load of the earth is an important construction machinery. It is with a rigid or flexible connection with the bucket, intermittent cycle repeated cycles of dredging machinery self-traveling homewo

64、rk.</p><p>　　Due to encouraging results of recent research, there are increasing possibilities for enhancement of a large spectrum human efforts in excavation processes. This may occur mainly through control

65、 of repetitive work tasks, such as trenching and drilling, requiring constant attention of machine operators during the performance of each task. Particular attention, in research, is paid to excavation along prescribed

66、trajectories subjected to varying soil environment. Fundamentals dealing with controll</p><p>　　With the continuous development of hydraulic transmission technology, perfect, hydraulic excavator single fight

67、s in the machinery industry growing proportion of production. Single hydraulic excavator are a hydraulic driving and a bucket to excavate the homework. Single hydraulic excavator with mining capacity, high universality,

68、can adapt the structural characteristics of different requirements. He is widely used in infrastructure projects.</p><p><b>　　關(guān)于液壓挖掘機(jī)</b></p><p>　　液壓挖掘機(jī)作為工程機(jī)械的代表產(chǎn)品在社會(huì)建設(shè)中發(fā)揮了巨大的作用，其中又以

69、全液壓履帶反鏟挖掘機(jī)的應(yīng)用最為廣泛，它在降低工作強(qiáng)度、保證施工質(zhì)量、提高勞動(dòng)生產(chǎn)率方面具有十分顯著的作用。工作裝置的性能是決定挖掘機(jī)能效高低的關(guān)鍵因素，它的設(shè)計(jì)好壞直接決定了挖掘機(jī)的性能水平。工作裝置是典型的機(jī)液結(jié)合部件，從機(jī)械和液壓兩個(gè)方面綜合考慮無(wú)疑是研究提高其性能合理而明智的方法。</p><p>　　液壓系統(tǒng)與動(dòng)力系統(tǒng)作為液壓挖掘機(jī)最重要的核心系統(tǒng)，其成本在整機(jī)中的比例也是最大的。液壓系統(tǒng)作為傳動(dòng)系統(tǒng)與能

70、量分配系統(tǒng)，直接決定了駕駛員大部分的操作感受。目前行業(yè)主要關(guān)注液壓系統(tǒng)在挖掘機(jī)中幾個(gè)方面的作用:(1)操縱特性與流量分配;(2)節(jié)能;(3)能量密度和可靠度的提高。</p><p>　　一個(gè)完整的液壓系統(tǒng)由五個(gè)部分組成，即動(dòng)力元件、執(zhí)行元件、控制元件、輔助元件（附件）和液壓油。動(dòng)力元件的作用是將原動(dòng)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(dòng)力。液壓泵的結(jié)構(gòu)形式一般有齒輪泵、葉片泵和柱

71、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(dòng)負(fù)載作直線往復(fù)運(yùn)動(dòng)或回轉(zhuǎn)運(yùn)動(dòng)。 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)

72、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、快換接頭、高壓球閥、膠管總成、測(cè)壓接頭、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。</p><p>　　一個(gè)液壓系統(tǒng)的好壞不僅取決于系統(tǒng)設(shè)計(jì)的合理性和系統(tǒng)元件性能的的優(yōu)劣，還因系統(tǒng)的污染防護(hù)和處理，系統(tǒng)的污染直接影響液壓系統(tǒng)工作的可靠性和元件的使用壽命，據(jù)統(tǒng)計(jì)

73、，國(guó)內(nèi)外的的液壓系統(tǒng)故障大約有70%是由于污染引起的。 </p><p>　　油液污染對(duì)系統(tǒng)的危害主要如下：</p><p><b>　　1）元件的污染磨損</b></p><p>　　油液中各種污染物引起元件各種形式的磨損，固體顆粒進(jìn)入運(yùn)動(dòng)副間隙中，對(duì)零件表面產(chǎn)生切削磨損或是疲勞磨損。高速液流中的固體顆粒對(duì)元件的表面沖擊引起沖蝕磨損。油液中的

74、水和油液氧化變質(zhì)的生成物對(duì)元件產(chǎn)生腐蝕作用。此外，系統(tǒng)的油液中的空氣引起氣蝕，導(dǎo)致元件表面剝蝕和破壞。</p><p>　　2）元件堵塞與卡緊故障</p><p>　　固體顆粒堵塞液壓閥的間隙和孔口，引起閥芯阻塞和卡緊，影響工作性能，甚至導(dǎo)致嚴(yán)重的事故。</p><p>　　3）加速油液性能的劣化</p><p>　　油液中的水和空氣以其熱能

75、是油液氧化的主要條件，而油液中的金屬微粒對(duì)油液的氧化起重要催化作用，此外，油液中的水和懸浮氣泡顯著降低了運(yùn)動(dòng)副間油膜的強(qiáng)度，使?jié)櫥阅芙档汀?lt;/p><p>　　一個(gè)系統(tǒng)在正式投入之前一般都要經(jīng)過(guò)沖洗，沖洗的目的就是要清除殘留在系統(tǒng)內(nèi)的污染物、金屬屑、纖維化合物、鐵心等，在最初兩小時(shí)工作中，即使沒(méi)有完全損壞系統(tǒng)，也會(huì)引起一系列故障。所以應(yīng)該按下列步驟來(lái)清洗系統(tǒng)油路： 　　</p><p>

76、　　1）用一種易干的清潔溶劑清洗油箱，再用經(jīng)過(guò)過(guò)濾的空氣清除溶劑殘?jiān)?　　</p><p>　　2）清洗系統(tǒng)全部管路，某些情況下需要把管路和接頭進(jìn)行浸漬。 　　</p><p>　　3）在管路中裝油濾，以保護(hù)閥的供油管路和壓力管路。 　　</p><p>　　4）在集流器上裝一塊沖洗板以代替精密閥，如電液伺服閥等。 　　</p><p>　

77、　5）檢查所有管路尺寸是否合適，連接是否正確。 </p><p>　　要是系統(tǒng)中使用到電液伺服閥，我不妨多說(shuō)兩句，伺服閥得沖洗板要使油液能從供油管路流向集流器，并直接返回油箱，這樣可以讓油液反復(fù)流通，以沖洗系統(tǒng)，讓油濾濾掉固體顆粒，沖洗過(guò)程中，沒(méi)隔1～2小時(shí)要檢查一下油濾，以防油濾被污染物堵塞，此時(shí)旁路不要打開，若是發(fā)現(xiàn)油濾開始堵塞就馬上換油濾。 　　沖洗的周期由系統(tǒng)的構(gòu)造和系統(tǒng)污染程度來(lái)決定，若過(guò)濾介質(zhì)的試樣沒(méi)

78、有或是很少外來(lái)污染物，則裝上新的油濾，卸下沖洗板，裝上閥工作！ 　　</p><p>　　有計(jì)劃的維護(hù)，建立系統(tǒng)定期維護(hù)制度，對(duì)液壓系統(tǒng)較好的維護(hù)保養(yǎng)建議如下： 　　</p><p>　　1）至多500小時(shí)或是三個(gè)月就要檢查和更換油液; 　　</p><p>　　2）定期沖洗油泵的進(jìn)口油濾; 　　</p><p>　　3）檢查液壓油被酸化或其

79、他污染物污染情況，液壓油的氣味可以大致鑒別是否變質(zhì); 　　</p><p>　　4）修護(hù)好系統(tǒng)中的泄漏; 　　</p><p>　　5）確保沒(méi)有外來(lái)顆粒從油箱的通氣蓋、油濾的塞座、回油管路的密封墊圈以及油箱其他開口處進(jìn)入油箱。</p><p>　　液壓系統(tǒng)泄漏的危害及控制</p><p>　　一、液壓系統(tǒng)泄漏的原因 　　 </p>

80、<p>　?。ǎ保┰O(shè)計(jì)及制造的缺陷所造成的； 　　 </p><p>　?。ǎ玻_擊和振動(dòng)造成管接頭松動(dòng)； 　　</p><p>　?。ǎ常﹦?dòng)密封件及配合件相互磨損（液壓缸尤甚）； 　　</p><p>　?。ǎ矗┯蜏剡^(guò)高及橡膠密封與液壓油不相容而變質(zhì)。下面就結(jié)合以上幾個(gè)方面淺談一下控制泄漏的措施。 　　</p><p>　　二

81、、控制液壓系統(tǒng)泄漏的控制方案 </p><p>　　液壓元件外配套的選擇往往在液壓系統(tǒng)的泄漏中起著決定性的影響。這就決定我們技術(shù)人員在新產(chǎn)品設(shè)計(jì)、老產(chǎn)品的改進(jìn)中，對(duì)缸、泵、閥件，密封件，液壓輔件等的選擇，要本著好中選優(yōu)，優(yōu)中選廉的原則慎重的、有比較的進(jìn)行。</p><p>　　靜密封件在剛性固定表面之間防止油液外泄。合理設(shè)計(jì)密封槽尺寸及公差，使安裝后的密封件到一定擠壓產(chǎn)生變形以便填塞配合表

82、面的微觀凹陷，并把密封件內(nèi)應(yīng)力提高到高于被密封的壓力。當(dāng)零件剛度或螺栓預(yù)緊力不夠大時(shí)，配合表面將在油液壓力作用下分離，造成間隙或加大由于密封表面不夠平而可能從開始就存在的間隙。隨著配合表面的運(yùn)動(dòng)，靜密封就成了動(dòng)密封。粗糙的配合表面將磨損密封件，變動(dòng)的間隙將蠶食密封件邊緣。</p><p>　　密封件過(guò)早變質(zhì)可能是由多種因素引起的，一個(gè)重要因素是油溫過(guò)高。溫度每升高１０℃則密封件壽命就會(huì)減半，所以應(yīng)合理設(shè)計(jì)高效液壓

83、系統(tǒng)或設(shè)置強(qiáng)制冷卻裝置，使最佳油液溫度保持在６５℃以下；工程機(jī)械不許超過(guò)８０℃；另一個(gè)因素可能是使用的油液與密封材料的相容性問(wèn)題，應(yīng)按使用說(shuō)明書或有關(guān)手冊(cè)選用液壓油和密封件的型式和材質(zhì)，以解決相容性問(wèn)題，延長(zhǎng)密封件的使用壽命。</p><p>　　操縱特性與流量分配是一對(duì)相互影響的因素。在先導(dǎo)液控條件下，各路流量的獨(dú)立性和每個(gè)油路的控制特性往往互有影響，一般要求液控先導(dǎo)手柄的操作直觀感受要與相應(yīng)油缸或馬達(dá)的動(dòng)作一

84、致，即是線性關(guān)系，這樣操作人員很容易上手。另一方面，一套系統(tǒng)中執(zhí)行器的數(shù)量往往大于獨(dú)立油源的數(shù)量，連接同一油源的執(zhí)行器同時(shí)動(dòng)作時(shí)它們之間必然會(huì)有相互影響，破壞各自工作時(shí)的獨(dú)立控制特性。日本小松(KOMATSU)九十年代以前一直致力于開發(fā)的開式系統(tǒng)，使用一個(gè)三位六通閥的兩個(gè)臺(tái)階同時(shí)對(duì)進(jìn)油油路和旁路油路進(jìn)行節(jié)流調(diào)速，這種系統(tǒng)閥芯位移與實(shí)際輸出流量關(guān)系復(fù)雜，并且還受負(fù)載和油源的影響，使得操縱性、微動(dòng)性能都不好，并不能解決實(shí)際使用復(fù)合動(dòng)作的需要

85、。由于操作手柄輸入與流量輸出不能保持一定的關(guān)系，隨時(shí)都在變化，裝備開式系統(tǒng)的挖掘機(jī)即使對(duì)于技術(shù)熟練的駕駛員操作起來(lái)也不是一件輕松的事。由于開式系統(tǒng)以上種種不適應(yīng)于挖掘機(jī)的特點(diǎn)，后來(lái)出現(xiàn)了閉式系統(tǒng)，其利用壓力補(bǔ)償?shù)姆椒▽?shí)現(xiàn)了供油路的定差減壓，能夠只用一個(gè)油源向所有執(zhí)行器供油，每個(gè)執(zhí)行器的速度只與操縱閥的閥桿行程有關(guān)，復(fù)合動(dòng)作時(shí)各路相互干擾小。在執(zhí)行器流量利用上，出現(xiàn)了利用回油補(bǔ)充供油油路以加</p><p>　　目

86、前挖掘機(jī)液壓系統(tǒng)節(jié)能的主要思想是調(diào)節(jié)泵的流量使之盡量接近負(fù)載的需求，不至于多出太多造成溢流損失。通常的做法是利用負(fù)載壓力的變化作為負(fù)反饋來(lái)調(diào)節(jié)變量泵的斜盤角，進(jìn)而控制泵的流量輸出，對(duì)于泵來(lái)說(shuō)從P口開始到執(zhí)行器都應(yīng)算是負(fù)載段，用于控制泵排量的反饋壓力所處的位置對(duì)于節(jié)能系統(tǒng)的性能也有影響，常見(jiàn)的負(fù)荷傳感系統(tǒng)是直接利用泵出口處的壓力來(lái)控制斜盤，這種系統(tǒng)的好處是反饋壓力離泵很近(反饋回路可能就是與泵做成一體的)，使調(diào)速節(jié)流壓差損失△P很小，微動(dòng)

87、性能好。另外一種功率調(diào)節(jié)反饋壓力取自主控閥后，離執(zhí)行器比較近，以日系廠家為代表的負(fù)流量系統(tǒng)就是采用這種形式，它的優(yōu)點(diǎn)主要是對(duì)負(fù)荷的響應(yīng)比較快，但是由于反饋壓力是由節(jié)流閥建立起來(lái)的，在低速重載時(shí)響應(yīng)不靈敏，可控性較差。</p><p>　　面對(duì)越來(lái)越高的功率需求，由于大流量會(huì)導(dǎo)致系統(tǒng)損失和體積的增加，液壓傳動(dòng)系統(tǒng)選擇的是向高壓方向發(fā)展，對(duì)于流量的需求則靠多泵并聯(lián)的方式解決，目前國(guó)外先進(jìn)挖掘機(jī)液壓元件額定壓力在30

88、MPa左右，這對(duì)密封、配合和油液的清潔度提出了更高的要求。在可靠性方面，通過(guò)理論與實(shí)驗(yàn)結(jié)合的方法，主要是針對(duì)泵、閥中配合面高精度配合摩擦的研究，通過(guò)對(duì)油液中摩擦微粒的分析不斷優(yōu)化元件設(shè)計(jì)。</p><p>　　由于液壓技術(shù)的應(yīng)用，20世紀(jì)40年代有了在拖拉機(jī)上配裝液壓反鏟的懸掛式挖掘機(jī)，20世紀(jì)50年代初期和中期相繼研制出拖式全回轉(zhuǎn)液壓挖掘機(jī)和履帶式全液壓挖掘機(jī)，初期試制的液壓挖掘機(jī)是采用飛機(jī)和機(jī)床的液壓技術(shù)，缺

89、少適用于挖掘機(jī)各種工況的液壓元件，制造質(zhì)量不夠穩(wěn)定，配套件也不齊全。從20世紀(jì)60年代起，液壓挖掘機(jī)進(jìn)入推廣和蓬勃發(fā)展階段，各國(guó)挖掘機(jī)制造廠和品種增加很快,產(chǎn)量猛增。1968～1970年間，液壓挖掘機(jī)產(chǎn)量已占挖掘機(jī)總產(chǎn)量的83％，目前已接近100％。</p><p>　　工業(yè)發(fā)達(dá)國(guó)家的挖掘機(jī)生產(chǎn)較早，法國(guó)、德國(guó)、美國(guó)、俄羅斯、日本等是斗容量3.5-40 m3單斗液壓挖掘機(jī)的主要生產(chǎn)國(guó)，從20世紀(jì)80年代開始生產(chǎn)特

90、大型挖掘機(jī)。例如，美國(guó)馬利昂公司生產(chǎn)的斗容量50-150 m3的剝離用挖掘機(jī)，斗容量132 m3的步行式拉鏟挖掘機(jī)；B-E公司生產(chǎn)的斗容量168.2 m3的步行式拉鏟挖掘機(jī)，斗容量107 m3的剝離用挖掘機(jī)等，是世界上目前最大的挖掘機(jī)。</p><p>　　從20世紀(jì)后期開始，國(guó)際上挖掘機(jī)的生產(chǎn)向大型化、微型化、多功能化、專用化和自動(dòng)化的方向發(fā)展。</p><p>　　1)開發(fā)多品種、多功

91、能、高質(zhì)量及高效率的挖掘機(jī)。為滿足市政建設(shè)和農(nóng)田建設(shè)的需要，國(guó)外發(fā)展了斗容量在O.25 m3以下的微型挖掘機(jī)，最小的斗容量?jī)HO01 m3。</p><p>　　2)迅速發(fā)展全液壓挖掘機(jī)，不斷改進(jìn)和革新控制方式，使挖掘機(jī)由簡(jiǎn)單的杠桿操縱發(fā)展到液壓操縱、氣壓操縱、液壓伺服操縱和電氣控制、無(wú)線電遙控、電子計(jì)算機(jī)綜合程序控制。</p><p>　　3)重視采用新技術(shù)、新工藝、新結(jié)構(gòu)，加快標(biāo)準(zhǔn)化、系

92、列化、通用化發(fā)展速度。例如，德國(guó)阿特拉斯公司生產(chǎn)的挖掘機(jī)裝有新型的發(fā)動(dòng)機(jī)轉(zhuǎn)速調(diào)節(jié)裝置，使挖掘機(jī)按最適合其作業(yè)要求的速度來(lái)工作；美國(guó)林肯一貝爾特公司新C系列LS-5800型液壓挖掘機(jī)安裝了全自動(dòng)控制液壓系統(tǒng)，可自動(dòng)調(diào)節(jié)流量，避免了驅(qū)動(dòng)功率的浪費(fèi)。還安裝了CAPS(計(jì)算機(jī)輔助功率系統(tǒng))，提高挖掘機(jī)的作業(yè)功率，更好地發(fā)揮液壓系統(tǒng)的功能；日本住友公司生產(chǎn)的FJ系列五種新型號(hào)挖掘機(jī)配有與液壓回路連接的計(jì)算機(jī)輔助的功率控制系統(tǒng)，利用精控模式選擇系統(tǒng)

93、，減少燃油、發(fā)動(dòng)機(jī)功率和液壓功率的消耗，并延長(zhǎng)了零部件的使用壽命；德國(guó)奧加凱(O&K)公司生產(chǎn)的挖掘機(jī)的油泵調(diào)節(jié)系統(tǒng)具有合流特性，使油泵具有最大的工作效率；日本神鋼公司在新型的904、905、907、909型液壓挖掘機(jī)上采用智能型控制系統(tǒng)，即使無(wú)經(jīng)驗(yàn)的駕駛員也能進(jìn)行復(fù)雜的作業(yè)操作；德國(guó)利勃海爾公司開發(fā)了ECO(電子控制作業(yè))的操縱裝置，可根據(jù)作業(yè)要求調(diào)節(jié)挖掘機(jī)的作業(yè)性能，取得了高效率、低油耗的效果；美國(guó)卡特匹勒公司在新型B系統(tǒng)挖

94、掘機(jī)上采用最新的3114T型柴油機(jī)以及扭矩載荷傳感壓力系統(tǒng)、功率方式選擇器等，</p><p>　　4)更新設(shè)計(jì)理論，提高可靠性，延長(zhǎng)使用壽命。美、英、日等國(guó)家推廣采用有限壽命設(shè)計(jì)理論，以替代傳統(tǒng)的無(wú)限壽命設(shè)計(jì)理論和方法，并將疲勞損傷累積理論、斷裂力學(xué)、有限元法、優(yōu)化設(shè)計(jì)、電子計(jì)算機(jī)控制的電液伺服疲勞試驗(yàn)技術(shù)、疲勞強(qiáng)度分析方法等先進(jìn)技術(shù)應(yīng)用于液壓挖掘機(jī)的強(qiáng)度研究方面，促進(jìn)了產(chǎn)品的優(yōu)質(zhì)高效率和競(jìng)爭(zhēng)力。</p&

95、gt;<p>　　5)加強(qiáng)對(duì)駕駛員的勞動(dòng)保護(hù)，改善駕駛員的勞動(dòng)條件。液壓挖掘機(jī)采用帶有墜物保護(hù)結(jié)構(gòu)和傾翻保護(hù)結(jié)構(gòu)的駕駛室，安裝可調(diào)節(jié)的彈性座椅，用隔音措施降低噪聲干擾。 </p><p>　　國(guó)內(nèi)小挖液壓元件配套采購(gòu)目標(biāo)主要還是國(guó)外知名品牌產(chǎn)品。導(dǎo)致這種現(xiàn)狀的主要原因是國(guó)產(chǎn)液壓系統(tǒng)在性能、可靠性方面與國(guó)外產(chǎn)品有不小差距，導(dǎo)致了國(guó)內(nèi)市場(chǎng)對(duì)國(guó)產(chǎn)元件缺乏認(rèn)同。目前國(guó)內(nèi)挖掘機(jī)液壓系統(tǒng)行業(yè)尚處在跟隨國(guó)外企業(yè)，

96、模仿學(xué)習(xí)的階段。</p><p>　　單斗挖掘機(jī)是挖掘和裝載土石的一種重要施工機(jī)械。它是用一個(gè)剛性或撓性聯(lián)結(jié)的鏟斗，以間歇重復(fù)的循環(huán)進(jìn)行周期作業(yè)的自行式土石方機(jī)械。根據(jù)最近的研究結(jié)果,人們致力于提高其挖掘過(guò)程，而這主要是通過(guò)可能出現(xiàn)重復(fù)的工作控制的任務(wù),如挖坑、鉆井、需要機(jī)器操作員不斷地注意在履行各項(xiàng)任務(wù)。特別值得注意的是,在研究中,對(duì)基坑開挖沿規(guī)定的軌跡受到不同土壤環(huán)境影響。</p><p&

97、gt;　　開挖過(guò)程控制的基礎(chǔ)理論主要有Vaha Skibniewski,Hemami,Hiller和Schnider討論。一個(gè)有用的方法直接打樁過(guò)程的角度提出了Keskinen遙感方法等。Budny和Gutkowski模型提供了一種系統(tǒng),采用對(duì)挖掘機(jī)鏟斗誘導(dǎo)的運(yùn)動(dòng)。在這種方法中,一個(gè)小的變化的影響,液壓油缸流入靈敏度分析的基礎(chǔ)上,討論了Gutkowski和Chlgosta，Huang等之間的關(guān)系,提出了控制研究阻抗機(jī)械液壓挖掘機(jī)應(yīng)用：一

98、、兩個(gè)神經(jīng)網(wǎng)絡(luò)作為反饋控制器和第二作為反饋目標(biāo)的阻抗。另一個(gè)阻抗的系統(tǒng),由Ha提出的采用混合位置力控制。 </p><p>　　第一代的機(jī)器人被視為“開環(huán)”定位裝置。這意味著所有的部件必須以一個(gè)非常高的準(zhǔn)確性。接下來(lái),定位的機(jī)器人,傳感器、減少這種精度要求這里有幾個(gè)方法,在上面提到的參考,延長(zhǎng)了工業(yè)機(jī)器人機(jī)械液壓挖掘能力。系統(tǒng)的力量,縱向和角速度傳感器單元已經(jīng)被應(yīng)用。然而,兩個(gè)主要的區(qū)別制造機(jī)器人要求挖掘機(jī)應(yīng)注意

99、。第一個(gè)區(qū)別在于制造機(jī)器人幾乎在完美的條件下, 自由振動(dòng)、免受沖擊、濕度和其他可能的破壞情況。第二個(gè)區(qū)別是要求制造機(jī)器人精度高,精確到微米。相反,機(jī)器人挖掘機(jī)是在非常惡劣地條件下工作，并且需要較高精度的執(zhí)行軌跡,具體的是到厘米。根據(jù)上述差異,探討控制基坑由液壓模塊組成的軌跡的泵和單向閥。換句話說(shuō),探討了系統(tǒng)的傳感器安裝在細(xì)胞的連線,加上挖掘機(jī)反饋控制器,包括在液壓裝置的機(jī)器。現(xiàn)在的主要目標(biāo)就是延長(zhǎng)了討論,由作者的可能性,在應(yīng)用單向閥安裝