喜歡就充值下載吧。。資源目錄里展示的文件全都有，，請(qǐng)放心下載，，有疑問(wèn)咨詢QQ:414951605或者1304139763 ======================== 喜歡就充值下載吧。。資源目錄里展示的文件全都有，，請(qǐng)放心下載，，有疑問(wèn)咨詢QQ:414951605或者1304139763 ======================== ..大學(xué).. 畢業(yè)論文（設(shè)計(jì)）任務(wù)書 論文（設(shè)計(jì)）題目： 摩托車液壓減震器設(shè)計(jì) 學(xué)號(hào)： .. 姓名： .. 專業(yè)： 機(jī)械設(shè)計(jì)制造及其自動(dòng)化 指導(dǎo)教師： ..教授 系主任： 一、主要內(nèi)容及基本要求 (1)基本掌握摩托車液壓減震器的組成及功能。 (2)掌握摩托車液壓減震器的基本知識(shí)。 (3)分析液壓減震器的原理，繪制原理圖。 (4)對(duì)液壓減震器的有關(guān)參數(shù)進(jìn)行計(jì)算，并繪制裝配圖，若干零件圖。 (5)翻譯一份有關(guān)本課題的3000字以上中英文文獻(xiàn)資料。 (6)設(shè)計(jì)說(shuō)明書8000字以上。 二、重點(diǎn)研究的問(wèn)題 分析液壓減震器的原理。 三、進(jìn)度安排 序號(hào) 各階段完成的內(nèi)容 完成時(shí)間 1 資料檢索、查詢 第1至2周 2 總體方案構(gòu)思設(shè)計(jì) 第3至4周 3 掌握減震器原理 第5至7周 4 完成減震器的相關(guān)參數(shù)設(shè)計(jì) 第8至12周 5 畢業(yè)論文撰寫和編輯 第13至14周 6 交畢業(yè)設(shè)計(jì)說(shuō)明書和圖紙，答辯準(zhǔn)備 第15周 四、應(yīng)收集的資料及主要參考文獻(xiàn) [1]陳守慶.摩托車減震器行業(yè)的現(xiàn)狀及發(fā)展策略[J]. 摩托車技術(shù)，2003，5：32-38 [2]張冰蔚，單春賢.摩托車減震器示功圖測(cè)試與分析[J]. 華東船舶工業(yè)學(xué)院學(xué)報(bào)， 2000，14(4)：59-62 [3]田茹會(huì), 王鐘羨. 改進(jìn)的遺傳算法在減震器優(yōu)化中的應(yīng)用[J]. 機(jī)械工程師，2006.(03) [4]摩托車技術(shù)[M].北京,機(jī)械工業(yè)出版社,2005 [5]單春賢,張冰蔚,陸　勇.摩托車前減震器阻尼特性數(shù)學(xué)模型的建立 江蘇理工大學(xué)學(xué)報(bào)，2001，22(5):26-32 [6]單春賢,仲敏波,吉恒松,邵　霞.摩托車筒式減震器液壓阻尼特性的模擬與仿真江蘇理工大學(xué)學(xué)報(bào),2007,28(1):26-34 [7]姜水生,文華,劉越琪.減震器特性的統(tǒng)計(jì)模擬研究[J].南昌大學(xué)學(xué)報(bào)，1999,21(2):9-29 [8]汪通悅.摩托車減震器動(dòng)力特性研究[J].現(xiàn)代機(jī)械，2000，4：56-60 [9]劉愛(ài)紅 ,茹小元.摩托車減震器總成靜載荷特性分析[J].摩托車技術(shù)，2005，4：11-14 [10]劉愛(ài)紅,賀陽(yáng).摩托車減震器阻力_速度特性曲線常用種類及應(yīng)用[J]. 摩托車技術(shù),2007,6:65-71 [11]楊基忠,俞大衛(wèi),葉全勇.減振器振動(dòng)系統(tǒng)穩(wěn)定性分析與研究[J].兵工學(xué)報(bào)，2000,77(1):43-56 [12]周　臻,何正琛.淺析摩托車減震器的_軟_與_硬_[J].成都航空職業(yè)技術(shù)學(xué)院學(xué)報(bào)，2004，60(3):79-83 [13]馬震來(lái). 汽車液壓減震器參數(shù)優(yōu)化設(shè)計(jì)[J]，2004.(3) [14]成大先，王德夫，姬奎生，韓學(xué)銓，姜勇，李長(zhǎng)順. 機(jī)械設(shè)計(jì)手冊(cè)[M]. 工業(yè)出版社，2002.(3) ..大學(xué).. 畢業(yè)論文（設(shè)計(jì)）評(píng)閱表 學(xué)號(hào) .. 姓名 .. 專業(yè) 機(jī)械設(shè)計(jì)制造及其自動(dòng)化 畢業(yè)論文（設(shè)計(jì)）題目： 摩托車液壓減震器設(shè)計(jì) 評(píng)價(jià)項(xiàng)目 評(píng) 價(jià) 內(nèi) 容 選題 1.是否符合培養(yǎng)目標(biāo)，體現(xiàn)學(xué)科、專業(yè)特點(diǎn)和教學(xué)計(jì)劃的基本要求，達(dá)到綜合訓(xùn)練的目的； 2.難度、份量是否適當(dāng)； 3.是否與生產(chǎn)、科研、社會(huì)等實(shí)際相結(jié)合。 能力 1.是否有查閱文獻(xiàn)、綜合歸納資料的能力； 2.是否有綜合運(yùn)用知識(shí)的能力； 3.是否具備研究方案的設(shè)計(jì)能力、研究方法和手段的運(yùn)用能力； 4.是否具備一定的外文與計(jì)算機(jī)應(yīng)用能力； 5.工科是否有經(jīng)濟(jì)分析能力。 論文 （設(shè)計(jì)）質(zhì)量 1.立論是否正確，論述是否充分，結(jié)構(gòu)是否嚴(yán)謹(jǐn)合理；實(shí)驗(yàn)是否正確，設(shè)計(jì)、計(jì)算、分析處理是否科學(xué)；技術(shù)用語(yǔ)是否準(zhǔn)確，符號(hào)是否統(tǒng)一，圖表圖紙是否完備、整潔、正確，引文是否規(guī)范； 2.文字是否通順，有無(wú)觀點(diǎn)提煉，綜合概括能力如何； 3.有無(wú)理論價(jià)值或?qū)嶋H應(yīng)用價(jià)值，有無(wú)創(chuàng)新之處。 綜 合 評(píng) 價(jià) 選題較具時(shí)代性和現(xiàn)實(shí)性。全文結(jié)構(gòu)安排合理。觀點(diǎn)表達(dá)基本準(zhǔn)確。全文內(nèi)容緊扣機(jī)械設(shè)計(jì)專業(yè)要求來(lái)寫，充分體現(xiàn)出機(jī)械設(shè)計(jì)專業(yè)特色。查閱的相關(guān)資料較多。但不足之處主要是屬于自己創(chuàng)新的東西還不多。 總體上符合畢業(yè)論文要求。 評(píng)閱人： 2012年5月 日 ..大學(xué).. 畢業(yè)論文（設(shè)計(jì)）鑒定意見(jiàn) 學(xué)號(hào)： .. 姓名： .. 專業(yè)： 機(jī)械設(shè)計(jì)制造及其自動(dòng)化 畢業(yè)論文（設(shè)計(jì)說(shuō)明書） 36 頁(yè) 圖 表 張 論文（設(shè)計(jì)）題目： 摩托車液壓減震器設(shè)計(jì) 內(nèi)容提要： 本課題是對(duì)摩托車減震器進(jìn)行系統(tǒng)設(shè)計(jì)，主要完成以下兩個(gè)內(nèi)容的研究： 1：摩托車減震器的工作原理，繪制原理圖 2：對(duì)摩托車減震器的結(jié)構(gòu)進(jìn)行分析設(shè)計(jì)，對(duì)有關(guān)參數(shù)進(jìn)行運(yùn)算論證。 指導(dǎo)教師評(píng)語(yǔ) ..同學(xué)于本次畢業(yè)設(shè)計(jì)過(guò)程中積極查找相關(guān)文獻(xiàn)、資料，按時(shí)完成老師要求，多與同學(xué)交流，雖水平仍有待提高，但總體表現(xiàn)良好，同意進(jìn)行答辯。 指導(dǎo)教師： 年 月 日 答辯簡(jiǎn)要情況及評(píng)語(yǔ) 答辯小組組長(zhǎng)： 年 月 日 答辯委員會(huì)意見(jiàn) 答辯委員會(huì)主任： 年 月 日 6 外文翻譯-原文部分 SHOCK ABSORBER 【Introduction】 Shock Absorber Damper (Vibration Damper), shock absorber spring is mainly used to suppress rebound after the shock-absorbing shocks when the shocks from the road. After uneven pavement, while shock-absorbing spring can filter road vibration, but the spring itself will have reciprocating motion, which is used to control this kind of shock absorber spring jumping.Shock absorber is too soft, the body will be jumping up and down, shock absorbers too hard or too much resistance will impede the normal work of the spring. Suspension system on the conversion process, the hardware and hardware to the shock absorber of the spring with, and the spring hardness is closely related with the weight, so heavier vehicles generally use the shock absorber hard.David cited the crankshaft and connected devices, used to counter the crankshaft torsional vibration (that is, by crank the ignition cylinder and twist the impact of the phenomenon). 【Classification】 Shock Absorber From the shock absorber damping materials have divided this point there are two types of hydraulic and pneumatic, as well as a variable-damping shock absorber. Now the shock absorbers are: 1. Rubber shock absorber; 2.Spring shock absorber; 3. air type shock absorber; 4. Oil air dampers; 5. the whole oil type shock absorbers. 【The structure of shock absorber】 The structure of shock absorber piston rod with a tube inserted in the tube-in-full of oil. Orifice Pistons have made have been separated from the piston space of two parts oil to each other.With viscous damping is through the oil produced Orifice, Orifice smaller, the greater the damping force, the greater the viscosity of oil, the greater the damping force. Orifice size if the same work faster when the shock absorber, the damping influence of the General Assembly had to absorb shocks.As a result, the exit of Orifice to set up a disk-shaped valve spring, when the pressure change when the top valve was opened, Orifice opening larger, smaller damping. As the piston is a two-way movement, so both sides are equipped with piston valve spring, respectively, called the compression valve and valve done. Shock absorber according to their structure can be divided into double and single tube-type. Binocular-type shock absorber means there are both inside and outside the two cylinders, pistons, including tube-in-movement, as a result of the entry and out piston rod, the volume of oil inside the cylinder increases with the contraction, it should be exchanged with the outer tube to maintain balance within the cylinder oil. So have a double shock absorber in the four-valve, that is, in addition to the above-mentioned two throttle piston, there are both inside and outside the tube in a complete exchange between the valve and the flow compensation valve. Compared with the double-type, single tube-type shock absorber simple structure, a reduction of a valve system. In the lower part of cylinder equipped with a floating piston, (the so-called floating piston rod means that there is no control over their movements), the following in the floating piston to form a sealed chamber, there are high-pressure nitrogen charge. As a result of the above-mentioned piston rod into and out of oil caused by a change in liquid height of floating through the floating piston to automatically adapt.In addition to the above-mentioned two types of shock absorber, there are adjustable shock absorber resistance. It can be changed through an external operation to the size of Orifice. Recently, the car will be electronically controlled shock absorber as a standard-type equipment, traveling through the sensor detection, and by a computer to calculate the best damping force, so that the damping force shock absorber to adjust automatically the work of institutions. The working principle of automobile shock absorbers: Suspension system components due to elastic vibration generated by the impact, in order to improve vehicle ride comfort, suspension elastic element in parallel with the installation of shock absorber for the attenuation of vibration, automotive suspension systems are used in hydraulic shock absorber damping , and its working principle is that when the frame (or body) and the inter-axle relative motion by vibration occur, the shock absorber piston moved up and down inside, shock absorber oil cavity will be repeated from one chamber to go through the various Another pore cavity flows.At this point hole wall and the friction between oil and oil of the internal friction between the molecules formed on the vibration damping force, so that vehicle vibration energy into heat oil, and then distributed by the shock absorber to absorb the atmosphere. Channel cross-section and in the oil change and other factors, the damping force with the frame and axle (or wheel) the relative velocity between the increase or decrease, and the viscosity of the oil. Shock absorber components and flexibility with ease to assume the task of the impact and vibration, the damping force is too large, flexible suspension will deteriorate, and even damage to shock absorber connector. Hence, the flexibility to adjust shock absorber components and this contradiction. (1) in the compression stroke (near the axle and frame each other), a smaller shock absorber damping force in order to give full play to the role of elastic elements of flexibility, ease the impact. At this time, play a major role in elastic elements. (2) trip done in suspension (axle and frame away from each other), shock absorber damping force should be large and rapid damping. (3) When the axle (or wheel) and the relative velocity between the axle is too large, the request can automatically increase the shock absorber fluid flow, so that damping force is always maintained within certain limits in order to avoid to put too much impact load. In the automotive suspension system is widely used in Shock Absorber, and done in the compression and all-day trip called the two-way play the role of the role of vibration-type shock absorber, as well as the use of the new shock absorber, which includes inflatable adjustable shock absorber and shock absorber resistance. The role of two-way Shock Absorber Description working principle. In the compression stroke, the wheels moved closer to the body means a motor vehicle, shock absorber by compression, when the shock absorber piston within 3 down. Under the piston chamber of volume reduction, oil rise, the flow of oil through the valve 8 into the piston chamber above (superior). On the piston rod cavity was taken up as part of a space, thus increasing the cavity volume is less than the inferior vena cava to reduce the volume of oil was on the compression valve 6 open, flows back to storage tank 5. These valves to form a suspension of oil-saving campaign by the compression of the damping force.Shock absorber in the journey done, the wheel is equivalent to far away from the body, the shock absorber by stretching. Shock absorber when the piston up. Increase the hydraulic piston chamber, the flow valve 8 closed, the cavity of the oil done away inferior vena cava inflow valve 4. Due to the existence of rod, since the cavity is not sufficient oil flow to the inferior vena cava with the increase in volume, under the instigation of a vacuum chamber generated, when the oil tanks in the open compensation valve 7 into the inferior vena supplement. As a result of these throttling valve in the role of suspension damping done to play the role of exercise. Done as a result of valve spring stiffness and pre-compression force greater than the design of the valve, in the same pressure, the valves done and the corresponding slot of the channel Changtong area contains less than the sum of the corresponding valves and compression Changtong channel cross-sectional area of the sum of the gap. This has done the trip have a shock absorber damping force is greater than the compression stroke damping force to the requirements of the rapid damping. Shock Absorber, prospects for the development of automotive components Auto parts as the basis of the automobile industry, the automotive industry is continuing to support the healthy development of the necessary factors. Especially now, the automotive industry is dynamic, full autonomy to carry out development and innovation, but also needs a strong support system as the parts. Own brand vehicles and technological innovation as the basis of the need for spare parts, parts of the independent innovation and development of automotive industry have a strong driving force, they are interactive, interaction, and there is no vehicle of their own brand, a powerful system components R & D innovation capability difficult to burst, there is no strong support system components, and independent brands forced to do difficult masterpiece. 2006 January to December, China total auto parts and accessories manufacturers to achieve a total industrial output value of 539,704,996 thousand, representing 34.35 percent increase over the same period the previous year; to achieve a total sales income 527,234,933 thousand, representing 34.71 percent increase over the same period the previous year; achieve a cumulative total of 32,605,652 thousand dollars profit, than the 46.79 percent increase over the same period the previous year; As of the end of December 2006, the entire industry the number of above-scale enterprises for 6142. 2007 January to November, China total auto parts and accessories manufacturers to achieve a total industrial output value of 683,525,503 thousand dollars more than the same period last year increased by 37.34%; to achieve a total sales income 663,529,269 thousand, representing an increase of 37.45 over the same period last year %; the realization of the cumulative total amount of 48,487,363 thousand dollars profit last year, an increase of 68.61 percent over the same period; as at the end of November 2007, the entire industry the number of above-scale enterprises for 7171. 2008 January to November, China auto parts and accessories manufacturing industry realized a total industrial output value of 865,835,708 thousand dollars more than the same period last year increased by 25.62%; to achieve a total sales income 837,913,601 thousand dollars more than the same period last year increased by 24.12% ; the realization of the cumulative total amount of 53,876,595 thousand dollars profit last year, an increase of 15.92 percent over the same period; as at the end of November 2008, the entire industry the number of above-scale enterprises for 8303. Auto parts manufacturers from the automotive parts business and the formation of specialized groups, is becoming a trend of globalization. The world leading automotive and auto parts enterprises, almost all in China, established a joint venture or wholly foreign owned enterprises, technology joint ventures have been more than 1000. Domestic scientific and technological content of a number of high-effective, large-scale enterprises of motor vehicles and parts have grown up gradually. International automotive industry with the introduction of parts of "globalization of procurement," Strategy and the implementation of the international cross-border car localization strategy, the domestic market will be huge gaps in parts accessories. By 2010, China domestic auto parts production will reach 7000 billion . At present, although the overall decline in the global economy, but the last four to five years in accordance with the actual procurement practice, the fruits of China procurement of a large number of companies is not as predictable as optimistic, almost 80% of companies do not achieve their purchasing and procurement costs down目標(biāo). With the revaluation of the RMB and the export tax rebate rate of decline, China is facing even greater pressure on the procurement, international buyers will be looking at the same time has been transferred to Vietnam, India, Thailand, Australia and other countries and regions. It appears from the above, China auto parts industry in the current financial crisis will accelerate the growth. 外文翻譯—譯文部分 減震器 【減震器簡(jiǎn)介】 　　減震器(Vibration Damper) ，減震器主要用來(lái)抑制彈簧吸震后反彈時(shí)的震蕩及來(lái)自路面的沖擊。在經(jīng)過(guò)不平路面時(shí)，雖然吸震彈簧可以過(guò)濾路面的震動(dòng)，但彈簧自身還會(huì)有往復(fù)運(yùn)動(dòng)，而減震器就是用來(lái)抑制這種彈簧跳躍的。減震器太軟，車身就會(huì)上下跳躍，減震器太硬就會(huì)帶來(lái)太大的阻力，妨礙彈簧正常工作。在關(guān)于懸掛系統(tǒng)的改裝過(guò)程中，硬的減震器要與硬的彈簧相搭配，而彈簧的硬度又與車重息息相關(guān)，因此較重的車一般采用較硬的減震器。與引震曲軸相接的裝置，用來(lái)抗衡曲軸的扭轉(zhuǎn)振動(dòng)(即曲軸受汽缸點(diǎn)火的沖擊力而扭動(dòng)的現(xiàn)象)。 【減震器的分類】 　　減震器從產(chǎn)生阻尼的材料這個(gè)角度劃分主要有液壓和充氣兩種，還有一種可變阻尼的減震器. 　　現(xiàn)在使用的減震器有： 　　1.橡皮減震器； 　　2.彈簧減震器； 　　3.空氣式減震器； 　　4.油液空氣式減震器； 5.全油液式減震器。 【減震器的結(jié)構(gòu)】 　　減振器的結(jié)構(gòu)是帶有活塞的活塞桿插入筒內(nèi)，在筒中充滿油。活塞上有節(jié)流孔，使得被活塞分隔出來(lái)的兩部分空間中的油可以互相補(bǔ)充。阻尼就是在具有粘性的油通過(guò)節(jié)流孔時(shí)產(chǎn)生的，節(jié)流孔越小，阻尼力越大，油的黏度越大，阻尼力越大。如果節(jié)流孔大小不變，當(dāng)減振器工作速度快時(shí)，阻尼過(guò)大會(huì)影響對(duì)沖擊的吸收。因此，在節(jié)流孔的出口處設(shè)置一個(gè)圓盤狀的板簧閥門，當(dāng)壓力變大時(shí)，閥門被頂開(kāi)，節(jié)流孔開(kāi)度變大，阻尼變小。由于活塞是雙向運(yùn)動(dòng)的，所以在活塞的兩側(cè)都裝有板簧閥門，分別叫做壓縮閥和伸張閥。 　　減振器按其結(jié)構(gòu)可分為雙筒式和單筒式。雙筒式是指減振器有內(nèi)外兩個(gè)筒，活塞在內(nèi)筒中運(yùn)動(dòng)，由于活塞桿的進(jìn)入與抽出，內(nèi)筒中油的體積隨之增大與收縮，因此要通過(guò)與外筒進(jìn)行交換來(lái)維持內(nèi)筒中油的平衡。所以雙筒減振器中要有四個(gè)閥，即除了上面提到的活塞上的兩個(gè)節(jié)流閥外，還有裝在內(nèi)外筒之間的完成交換作用的流通閥和補(bǔ)償閥。 　　與雙筒式相比，單筒式減振器結(jié)構(gòu)簡(jiǎn)單，減少了一套閥門系統(tǒng)。它在缸筒的下部裝有一個(gè)浮動(dòng)活塞，(所謂浮動(dòng)即指沒(méi)有活塞桿控制其運(yùn)動(dòng))，在浮動(dòng)活塞的下面形成一個(gè)密閉的氣室，充有高壓氮?dú)?。上面提到的由于活塞桿進(jìn)出油液而造成的液面高度變化就通過(guò)浮動(dòng)活塞的浮動(dòng)來(lái)自動(dòng)適應(yīng)之。除了上面所述兩種減振器外，還有阻力可調(diào)式減振器。它可通過(guò)外部操作來(lái)改變節(jié)流孔的大小。最近的汽車將電子控制式減振器作為標(biāo)準(zhǔn)裝備，通過(guò)傳感器檢測(cè)行駛狀態(tài)，由計(jì)算機(jī)計(jì)算出最佳阻尼力，使減振器上的阻尼力調(diào)整機(jī)構(gòu)自動(dòng)工作。 　　汽車減震器的工作原理: 　　懸架系統(tǒng)中由于彈性元件受沖擊產(chǎn)生振動(dòng)，為改善汽車行駛平順性，懸架中與彈性元件并聯(lián)安裝減振器，為衰減振動(dòng)，汽車懸架系統(tǒng)中采用減振器多是液力減振器，其工作原理是當(dāng)車架（或車身）和車橋間受振動(dòng)出現(xiàn)相對(duì)運(yùn)動(dòng)時(shí)，減振器內(nèi)的活塞上下移動(dòng)，減振器腔內(nèi)的油液便反復(fù)地從一個(gè)腔經(jīng)過(guò)不同的孔隙流入另一個(gè)腔內(nèi)。此時(shí)孔壁與油液間的摩擦和油液分子間的內(nèi)摩擦對(duì)振動(dòng)形成阻尼力，使汽車振動(dòng)能量轉(zhuǎn)化為油液熱能，再由減振器吸收散發(fā)到大氣中。在油液通道截面和等因素不變時(shí)，阻尼力隨車架與車橋（或車輪）之間的相對(duì)運(yùn)動(dòng)速度增減，并與油液粘度有關(guān)。 　　減振器與彈性元件承擔(dān)著緩沖擊和減振的任務(wù)，阻尼力過(guò)大，將使懸架彈性變壞，甚至使減振器連接件損壞。因面要調(diào)節(jié)彈性元件和減振器這一矛盾。 　　(1) 在壓縮行程（車橋和車架相互靠近），減振器阻尼力較小，以便充分發(fā)揮彈性元件的彈性作用，緩和沖擊。這時(shí)，彈性元件起主要作用。 　　(2) 在懸架伸張行程中（車橋和車架相互遠(yuǎn)離），減振器阻尼力應(yīng)大，迅速減振。 　　(3) 當(dāng)車橋（或車輪）與車橋間的相對(duì)速度過(guò)大時(shí)，要求減振器能自動(dòng)加大液流量，使阻尼力始終保持在一定限度之內(nèi)，以避免承受過(guò)大的沖擊載荷。 　　在汽車懸架系統(tǒng)中廣泛采用的是筒式減振器，且在壓縮和伸張行程中均能起減振作用叫雙向作用式減振器，還有采用新式減振器，它包括充氣式減振器和阻力可調(diào)式減振器。 　　雙向作用筒式減振器工作原理說(shuō)明。在壓縮行程時(shí)，指汽車車輪移近車身，減振器受壓縮，此時(shí)減振器內(nèi)活塞3向下移動(dòng)。活塞下腔室的容積減少，油壓升高，油液流經(jīng)流通閥8流到活塞上面的腔室（上腔）。上腔被活塞桿1占去了一部分空間，因而上腔增加的容積小于下腔減小的容積，一部分油液于是就推開(kāi)壓縮閥6，流回貯油缸5。這些閥對(duì)油的節(jié)約形成懸架受壓縮運(yùn)動(dòng)的阻尼力。減振器在伸張行程時(shí)，車輪相當(dāng)于遠(yuǎn)離車身，減振器受拉伸。這時(shí)減振器的活塞向上移動(dòng)?；钊锨挥蛪荷?，流通閥8關(guān)閉，上腔內(nèi)的油液推開(kāi)伸張閥4流入下腔。由于活塞桿的存在，自上腔流來(lái)的油液不足以充滿下腔增加的容積，主使下腔產(chǎn)生一真空度，這時(shí)儲(chǔ)油缸中的油液推開(kāi)補(bǔ)償閥7流進(jìn)下腔進(jìn)行補(bǔ)充。由于這些閥的節(jié)流作用對(duì)懸架在伸張運(yùn)動(dòng)時(shí)起到阻尼作用。 　　由于伸張閥彈簧的剛度和預(yù)緊力設(shè)計(jì)的大于壓縮閥，在同樣壓力作用下，伸張閥及相應(yīng)的常通縫隙的通道載面積總和小于壓縮閥及相應(yīng)常通縫隙通道截面積總和。這使得減振器的伸張行程產(chǎn)生的阻尼力大于壓縮行程的阻尼力，達(dá)到迅速減振的要求。 [編輯本段]減振器、汽車零部件的發(fā)展前景 汽車零部件作為汽車工業(yè)的基礎(chǔ)，是支撐汽車工業(yè)持續(xù)健康發(fā)展的必要因素。特別是當(dāng)前汽車行業(yè)正在轟轟烈烈、如火如荼開(kāi)展的自主開(kāi)發(fā)與創(chuàng)新，更需要一個(gè)強(qiáng)大的零部件體系作支撐。整車自主品牌與技術(shù)創(chuàng)新需要零部件作基礎(chǔ)，零部件的自主創(chuàng)新又對(duì)整車產(chǎn)業(yè)的發(fā)展產(chǎn)生強(qiáng)大推動(dòng)力，他們是相互影響、相互作用的，沒(méi)有整車的自主品牌，強(qiáng)大零部件體系的研發(fā)創(chuàng)新能力難以迸發(fā)，沒(méi)有強(qiáng)大零部件體系的支撐，自主品牌的做大作強(qiáng)將難以為繼。 　　2006年1-12月，中國(guó)全部汽車零部件及配件制造企業(yè)實(shí)現(xiàn)累計(jì)工業(yè)總產(chǎn)值539,704,996千元，比上年同期增長(zhǎng)34.35%；實(shí)現(xiàn)累計(jì)產(chǎn)品銷售收入527,234,933千元，比上年同期增長(zhǎng)34.71%；實(shí)現(xiàn)累計(jì)利潤(rùn)總額為32,605,652千元，比上年同期增長(zhǎng)46.79%；截止到2006年12月底，全行業(yè)規(guī)模以上企業(yè)數(shù)量為6142家。 　　2007年1-11月，中國(guó)全部汽車零部件及配件制造企業(yè)實(shí)現(xiàn)累計(jì)工業(yè)總產(chǎn)值683,525,503千元，比上年同期增長(zhǎng)了37.34%；實(shí)現(xiàn)累計(jì)產(chǎn)品銷售收入663,529,269千元，比上年同期增長(zhǎng)了37.45%；實(shí)現(xiàn)累計(jì)利潤(rùn)總額48,487,363千元，比上年同期增長(zhǎng)了68.61%；截至2007年11月底，全行業(yè)規(guī)模以上企業(yè)數(shù)量為7171家。 　　2008年1-11月，中國(guó)汽車零部件及配件制造行業(yè)實(shí)現(xiàn)累計(jì)工業(yè)總產(chǎn)值865,835,708千元，比上年同期增長(zhǎng)了25.62%；實(shí)現(xiàn)累計(jì)產(chǎn)品銷售收入837,913,601千元，比上年同期增長(zhǎng)了24.12%；實(shí)現(xiàn)累計(jì)利潤(rùn)總額53,876,595千元，比上年同期增長(zhǎng)了15.92%；截至2008年11月底，全行業(yè)規(guī)模以上企業(yè)數(shù)量為8303家。 汽車零部件生產(chǎn)企業(yè)脫離整車企業(yè)并形成專業(yè)化零部件集團(tuán)，正成為一種全球化趨勢(shì)。國(guó)際著名的汽車及零部件企業(yè)，幾乎都在中國(guó)建立了合資或獨(dú)資企業(yè)，引進(jìn)技術(shù)合資企業(yè)已超過(guò)1000家。國(guó)內(nèi)一批科技含量高、效益好、規(guī)模大的汽車及零部件企業(yè)逐步成長(zhǎng)起來(lái)。隨著國(guó)際上汽車行業(yè)開(kāi)始實(shí)行零部件“全球化采購(gòu)”策略及國(guó)際跨國(guó)汽車企業(yè)推行本土化策略，國(guó)內(nèi)市場(chǎng)將出現(xiàn)巨大的零部件配件缺口。到2010年，中國(guó)汽車零部件國(guó)內(nèi)產(chǎn)值將達(dá)到7000億元左右。 目前，雖然全球經(jīng)濟(jì)整體下滑，但根據(jù)近四到五年的實(shí)際采購(gòu)實(shí)踐，中國(guó)采購(gòu)的成果并不像大量公司預(yù)測(cè)的那樣樂(lè)觀，幾乎80%以上的公司沒(méi)有達(dá)到他們采購(gòu)量和采購(gòu)降成本的目標(biāo)。而隨著人民幣升值和出口退稅率的下降，中國(guó)采購(gòu)面臨的壓力更大，國(guó)際采購(gòu)商已經(jīng)將目光同時(shí)轉(zhuǎn)移到越南、印度、泰國(guó)、澳大利亞等其它國(guó)家與地區(qū)。從以上看來(lái)，中國(guó)的汽車零部件產(chǎn)業(yè)在當(dāng)前的金融危機(jī)下仍將加速增長(zhǎng)。 7