同步液壓缸試驗(yàn)臺(tái)設(shè)計(jì)
同步液壓缸試驗(yàn)臺(tái)設(shè)計(jì),同步,液壓缸,試驗(yàn)臺(tái),設(shè)計(jì)
附錄
Hydraulic Technology in Industry
Hydraulic technology generally used in heavy, large, extra large equipment, such as metallurgical industry, rolling mill gauge control system, continuous casting machine pressure systems.
Military situation in the high-speed response, such as aircraft rudder control, ship steering control, high-speed response with the dynamic system.
Construction machinery, impact, required a relatively high power systems are generally heavy hydraulic systems.
Application of the above three areas are the best in the field of hydraulic technology Pressure transmission control is often used in industry as a control method, which uses hydraulic pressure to complete the process of transfer of energy. Hydraulic control method for the flexibility and convenience, the hydraulic control in the industry are widely appreciated. Is to study the hydraulic fluid to a pressure medium for the energy to achieve a variety of mechanical and control subjects. Hydraulic components used to form such a variety of control loops required, then a number of circuits, some combination of a complete transmission system control functions to accomplish energy transfer, conversion and control.
Theoretically, the hydraulic transmission is based on the most basic principle is the Pascal principle, that is, fluid pressure is the same everywhere, so in a balanced system, the relatively small pressure above the piston is relatively small, but large piston pressure is relatively large, it can still maintain a liquid. So, passing through the liquid, can be different on different side pressures, so that you can achieve a change of purpose. Our common to the hydraulic jack is used to achieve the power of this principle of transmission.
The basic principles of hydraulic.
Hydraulic components needed in the main power components, the implementation of components, control components, auxiliary components, etc.. One hydraulic power hydraulic system components for the power components, including a variety of hydraulic pumps. Pump principle to rely on changes in work volume, it is generally also known as volume hydraulic pump. Gear pump is the most common type of hydraulic pump that uses two rotating gears meshing allows the liquid to exercise. There are other hydraulic vane pump, piston pumps, hydraulic pump, when in the choice of the main issues requiring attention include the consumption of energy, efficiency and reduce noise.
Hydraulic actuator is used to perform the hydraulic pump to provide hydraulic energy into mechanical energy devices, including hydraulic cylinders and hydraulic motors. Hydraulic pump hydraulic motor is doing the opposite of work with the device, that is, the hydraulic energy conversion is called mechanical energy to do work outside.
Hydraulic control unit to control the direction of liquid flow, pressure, flow level and the size of the expected controls to meet specific job requirements. It is because of the flexibility of hydraulic control components, make hydraulic control system to perform different activities. Hydraulic control components in accordance with the purpose can be divided into pressure control valves, flow control valves, directional control valves. In accordance with the mode of operation can be divided into human control valve, mechanical control method, electric control valve.
In addition to the other components, hydraulic control system also needs auxiliary hydraulic components. These components include piping and fittings, tanks, filters, accumulators, and seal. All the above devices, we can build a hydraulic circuit. The so-called hydraulic circuit is formed through a variety of hydraulic devices corresponding control circuit. Depending on the control objectives, we can design different circuits, such as pressure control loop, speed control loop, multi-cylinder control circuit, etc. work.
According to the structure and characteristics of hydraulic transmission, the hydraulic system design, system analysis first, then develop the system diagram, which is the schematic symbol to represent the hydraulic machinery. After selection by calculating the hydraulic device, which can then complete the system design and debugging. This process, the principle of mapping is the key. It determines the merits of a design system.
The application of hydraulic transmission is very strong, such as loading and unloading stacking machine hydraulic system, which as a storage machine, in the modern warehouse use it to achieve textile bags, barrels, casks and other cargo handling is mechanical. Can also be used in universal cylindrical grinding machine hydraulic system and other production practices. These systems are characterized by relatively large power, more efficient production, stability is better.
As a widely used hydraulic technology, the future is a bright future. With the deepening development of a computer, hydraulic control system can intelligent control technology, computer technology, control technology together, so that more places will be able to play a role, but also can be more compact, more flexible to accomplish the tasks expected of control tasks.
Hydraulic fluid power transmission is one of the basic principle is in a closed container, the pressure of the oil used as a working medium to achieve energy conversion and transmission of power. One of the liquid as the working medium, usually mineral oil, its role and mechanical transmission of the belts, chains and gears and other transmission components are similar.
Hydraulic system consists of: Power components (pumps), the implementation of components (cylinder or hydraulic motor), control elements (all valve), auxiliary components and the work of the five media components.
Advantages and disadvantages of hydraulic
1、 the advantages of hydraulic
(1) small size, light in weight, so less inertia, when a sudden overload or stop when the big impact will not occur;
(2) can be stable within a given range automatically adjust traction speed, and can realize stepless speed regulation;
(3) for the easy, without changing the motor rotation direction of the case, you can more easily work agencies to achieve the reciprocating motion of rotation and conversion;
(4) hydraulic pump and a pipeline between the hydraulic motor connected to each other in space without strict limits on the layout;
(5) The use of oil as the working medium, the relative motion between the surface components can self-lubricating, wear small, long life;
(6) easy manipulation of control, high degree of automation;
(7) easy to implement overload protection.
2、 hydraulic transmission defects
(1) the use of hydraulic transmission requirements on the maintenance of high oil should always work to keep clean;
(2) manufacture of high precision hydraulic components, process complexity, high cost;
(3) maintenance of more complex hydraulic components, and the need for a higher technical level;
(4) oil to do the work of media, the existence of fire hazards in the face;
(5) The transmission efficiency is low.
液壓技術(shù)在工業(yè)中的應(yīng)用
液壓技術(shù)一般應(yīng)用于重型,大型,特大型設(shè)備,如冶金行業(yè)軋機(jī)壓下系統(tǒng),連鑄機(jī)壓下系統(tǒng)等。
軍工中高速響應(yīng)場合,如飛機(jī)尾舵控制,輪船舵機(jī)控制,高速響應(yīng)隨動(dòng)系統(tǒng)等
工程機(jī)械,抗沖擊,要求功重比較高系統(tǒng)一般都采用液壓系統(tǒng)。
以上三個(gè)領(lǐng)域是應(yīng)用液壓技術(shù)的最大領(lǐng)域。
壓傳動(dòng)控制是工業(yè)中經(jīng)常用到的一種控制方式,它采用液壓完成傳遞能量的過程。因?yàn)橐簤簜鲃?dòng)控制方式的靈活性和便捷性,液壓控制在工業(yè)上受到廣泛的重視。液壓傳動(dòng)是研究以有壓流體為能源介質(zhì),來實(shí)現(xiàn)各種機(jī)械和自動(dòng)控制的學(xué)科。液壓傳動(dòng)利用這種元件來組成所需要的各種控制回路,再由若干回路有機(jī)組合成為完成一定控制功能的傳動(dòng)系統(tǒng)來完成能量的傳遞、轉(zhuǎn)換和控制。
從原理上來說,液壓傳動(dòng)所基于的最基本的原理就是帕斯卡原理,就是說,液體各處的壓強(qiáng)是一致的,這樣,在平衡的系統(tǒng)中,比較小的活塞上面施加的壓力比較小,而大的活塞上施加的壓力也比較大,這樣能夠保持液體的靜止。所以通過液體的傳遞,可以得到不同端上的不同的壓力,這樣就可以達(dá)到一個(gè)變換的目的。我們所常見到的液壓千斤頂就是利用了這個(gè)原理來達(dá)到力的傳遞。
液壓傳動(dòng)基本原理。
液壓傳動(dòng)中所需要的元件主要有動(dòng)力元件、執(zhí)行元件、控制元件、輔助元件等。其中液壓動(dòng)力元件是為液壓系統(tǒng)產(chǎn)生動(dòng)力的部件,主要包括各種液壓泵。液壓泵依靠容積變化原理來工作,所以一般也稱為容積液壓泵。齒輪泵是最常見的一種液壓泵,它通過兩個(gè)嚙合的齒輪的轉(zhuǎn)動(dòng)使得液體進(jìn)行運(yùn)動(dòng)。其他的液壓泵還有葉片泵、柱塞泵,在選擇液壓泵的時(shí)候主要需要注意的問題包括消耗的能量、效率、降低噪音。
液壓執(zhí)行元件是用來執(zhí)行將液壓泵提供的液壓能轉(zhuǎn)變成機(jī)械能的裝置,主要包括液壓缸和液壓馬達(dá)。液壓馬達(dá)是與液壓泵做相反的工作的裝置,也就是把液壓的能量轉(zhuǎn)換稱為機(jī)械能,從而對(duì)外做功。
液壓控制元件用來控制液體流動(dòng)的方向、壓力的高低以及對(duì)流量的大小進(jìn)行預(yù)期的控制,以滿足特定的工作要求。正是因?yàn)橐簤嚎刂圃骷撵`活性,使得液壓控制系統(tǒng)能夠完成不同的活動(dòng)。液壓控制元件按照用途可以分成壓力控制閥、流量控制閥、方向控制閥。按照操作方式可以分成人力操縱閥、機(jī)械操縱法、電動(dòng)操縱閥等。
除了上述的元件以外,液壓控制系統(tǒng)還需要液壓輔助元件。這些元件包括管路和管接頭、油箱、過濾器、蓄能器和密封裝置。通過以上的各個(gè)器件,我們就能夠建設(shè)出一個(gè)液壓回路。所謂液壓回路就是通過各種液壓器件構(gòu)成的相應(yīng)的控制回路。根據(jù)不同的控制目標(biāo),我們能夠設(shè)計(jì)不同的回路,比如壓力控制回路、速度控制回路、多缸工作控制回路等。
根據(jù)液壓傳動(dòng)的結(jié)構(gòu)及其特點(diǎn),在液壓系統(tǒng)的設(shè)計(jì)中,首先要進(jìn)行系統(tǒng)分析,然后擬定系統(tǒng)的原理圖,其中這個(gè)原理圖是用液壓機(jī)械符號(hào)來表示的。之后通過計(jì)算選擇液壓器件,進(jìn)而再完成系統(tǒng)的設(shè)計(jì)和調(diào)試。這個(gè)過程中,原理圖的繪制是最關(guān)鍵的。它決定了一個(gè)設(shè)計(jì)系統(tǒng)的優(yōu)劣。
液壓傳動(dòng)的應(yīng)用性是很強(qiáng)的,比如裝卸堆碼機(jī)液壓系統(tǒng),它作為一種倉儲(chǔ)機(jī)械,在現(xiàn)代化的倉庫里利用它實(shí)現(xiàn)紡織品包、油桶、木桶等貨物的裝卸機(jī)械化工作。也可以應(yīng)用在萬能外圓磨床液壓系統(tǒng)等生產(chǎn)實(shí)踐中。這些系統(tǒng)的特點(diǎn)是功率比較大,生產(chǎn)的效率比較高,平穩(wěn)性比較好。
液壓作為一個(gè)廣泛應(yīng)用的技術(shù),在未來更是有廣闊的前景。隨著計(jì)算機(jī)的深入發(fā)展,液壓控制系統(tǒng)可以和智能控制的技術(shù)、計(jì)算機(jī)控制的技術(shù)等技術(shù)結(jié)合起來,這樣就能夠在更多的場合中發(fā)揮作用,也可以更加精巧的、更加靈活地完成預(yù)期的控制任務(wù)。
液壓傳動(dòng)是流體傳動(dòng)的一種,其基本原理是在密閉的容器內(nèi),利用有壓力的油液作為工作介質(zhì)來實(shí)現(xiàn)能量轉(zhuǎn)換和傳遞動(dòng)力的。其中的液體稱為工作介質(zhì),一般為礦物油,它的作用和機(jī)械傳動(dòng)中的皮帶、鏈條和齒輪等傳動(dòng)元件相類似。
液壓系統(tǒng)主要由:動(dòng)力元件(油泵)、執(zhí)行元件(油缸或液壓馬達(dá))、控制元件(各種閥)、輔助元件和工作介質(zhì)等五部分組成。
液壓傳動(dòng)的優(yōu)缺點(diǎn)
1、液壓傳動(dòng)的優(yōu)點(diǎn)
(1)體積小、重量輕,因此慣性力較小,當(dāng)突然過載或停車時(shí),不會(huì)發(fā)生大的沖擊;
(2)能在給定范圍內(nèi)平穩(wěn)的自動(dòng)調(diào)節(jié)牽引速度,并可實(shí)現(xiàn)無極調(diào)速;
(3)換向容易,在不改變電機(jī)旋轉(zhuǎn)方向的情況下,可以較方便地實(shí)現(xiàn)工作機(jī)構(gòu)旋轉(zhuǎn)和直線往復(fù)運(yùn)動(dòng)的轉(zhuǎn)換;
(4)液壓泵和液壓馬達(dá)之間用油管連接,在空間布置上彼此不受嚴(yán)格限制;
(5)由于采用油液為工作介質(zhì),元件相對(duì)運(yùn)動(dòng)表面間能自行潤滑,磨損小,使用壽命長;
(6)操縱控制簡便,自動(dòng)化程度高;
(7)容易實(shí)現(xiàn)過載保護(hù)。
2、液壓傳動(dòng)的缺點(diǎn)
(1)使用液壓傳動(dòng)對(duì)維護(hù)的要求高,工作油要始終保持清潔;
(2)對(duì)液壓元件制造精度要求高,工藝復(fù)雜,成本較高;
(3)液壓元件維修較復(fù)雜,且需有較高的技術(shù)水平;
(4)用油做工作介質(zhì),在工作面存在火災(zāi)隱患;
(5)傳動(dòng)效率低。
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