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本科畢業(yè)設(shè)計(jì)任務(wù)書 系 別 機(jī)電工程學(xué)院汽車系 專業(yè) 班級(jí) 學(xué)生姓名 學(xué)號(hào) 指導(dǎo)教師 職稱 題 目 車用雙向作用筒式減震器設(shè)計(jì) 論文（設(shè)計(jì)）的主要任務(wù)與具體要求（有實(shí)驗(yàn)環(huán)節(jié)的要提出主要技術(shù)指標(biāo)要求） 減震器又稱緩沖器，是安裝在車輛懸掛裝置上的一個(gè)重要零件。懸掛裝置不僅決定了乘坐的舒適度，而且還是決定其運(yùn)動(dòng)性能的重要部件。而減震器的功能就是緩和由于路面不平引起的沖擊，衰減摩車輛的振動(dòng)；提高乘坐舒適性，保護(hù)貨載；減低車體各部分的運(yùn)應(yīng)力，增加零件的壽命；加強(qiáng)輪胎的附著性，有助于車輛的操縱性、穩(wěn)定性。 設(shè)計(jì)要求：選定某轎車車型，設(shè)計(jì)一個(gè)液壓式雙向作用前減震器。工作行程5cm. 雙向作用筒式減振器示意圖： 工作原理說明。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)?；钊虑皇业娜莘e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撸魍ㄩy8關(guān)閉，上腔內(nèi)的油液推開伸張閥4流入下腔。由于活塞桿的存在，自上腔流來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。 主要任務(wù)： （1）機(jī)械總裝配圖若干張； （2）全部零件圖若干張； （3）設(shè)計(jì)說明書一份，要求對(duì)減震器參數(shù)的選擇有詳細(xì)的理論分析。 （總圖紙量達(dá)到教學(xué)大綱要求的工作量） 進(jìn)度安排（包括時(shí)間劃分和各階段主要工作內(nèi)容） 1．第七學(xué)期第11—12 周 交開題報(bào)告 2． 第七學(xué)期第13—20周 進(jìn)行具體畢業(yè)設(shè)計(jì)初稿； 3． 第七學(xué)期第18周 交畢業(yè)設(shè)計(jì)指導(dǎo)老師初步檢查 4．第八學(xué)期第3周 交畢業(yè)設(shè)計(jì)指導(dǎo)老師中期檢查 5．第八學(xué)期第7-8周 審查、修改互動(dòng)工作， 6．2016年4月24日前， 完成全部設(shè)計(jì)任務(wù)，交畢業(yè)設(shè)計(jì)； 7．第八學(xué)期第10周前 畢業(yè)論文（設(shè)計(jì)）答辯； 主要參考文獻(xiàn) （1） 周長城,《汽車液壓筒式減振器設(shè)計(jì)及理論》，北京大學(xué)出版社2012年 （2） 蔡興旺，《汽車構(gòu)造與原理》（下冊 底盤、車身）機(jī)械工業(yè)出版社，2004年； （3） 陳倩倩，《汽車液壓減震器的設(shè)計(jì)》 ，西南交通大學(xué)機(jī)械工程學(xué)院。 （4）王望予，《汽車設(shè)計(jì)》，機(jī)械工業(yè)出版社，2006年； 指導(dǎo)教師簽名 教研室審核意見 系審核意見 任務(wù)接受人（簽名） 年 月 日 負(fù)責(zé)人： 年 月 日 負(fù)責(zé)人： 年 月 日 年 月 日 備注：1、本任務(wù)書一式三份，由指導(dǎo)教師填寫相關(guān)欄目，經(jīng)系審核同意后，系、指導(dǎo)教師和學(xué)生各執(zhí)一份。 2、本任務(wù)書須裝入學(xué)生的畢業(yè)設(shè)計(jì)（論文）檔案袋存檔。 外文翻譯 減震器 減震器(Absorber) ，減震器主要用來抑制彈簧吸震后反彈時(shí)的震蕩及來自路面的沖擊。在經(jīng)過不平路面時(shí)，雖然吸震彈簧可以過濾路面的震動(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，用來抗衡曲軸的扭轉(zhuǎn)震動(dòng)(即曲軸受汽缸點(diǎn)火的沖擊力而扭動(dòng)的現(xiàn)象)。 減震器的名詞解釋 減震器(Absorber) ，減震器主要用來抑制彈簧吸震后反彈時(shí)的震蕩及來自路面的沖擊。 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)生震動(dòng)，為改善汽車行駛平順性，懸架中與彈性元件并聯(lián)安裝減震器，為衰減震動(dòng)，汽車懸架系統(tǒng)中采用減震器多是液力減震器，其工作原理是當(dāng)車架(或車身)和車橋間震動(dòng)而出現(xiàn)相對(duì)運(yùn)動(dòng)時(shí)，減震器內(nèi)的活塞上下移動(dòng)，減震器腔內(nèi)的油液便反復(fù)地從一個(gè)腔經(jīng)過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)震動(dòng)形成阻尼力，使汽車震動(dòng)能量轉(zhuǎn)化為油液熱能，再由減震器吸收散發(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)。 減震器與彈性元件承擔(dān)著緩沖擊和減震的任務(wù)，阻尼力過大，將使懸架彈性變壞，甚至使減震器連接件損壞。因面要調(diào)節(jié)彈性元件和減震器這一矛盾。 (1) 在壓縮行程(車橋和車架相互靠近)，減震器阻尼力較小，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)，減震器阻尼力應(yīng)大，迅速減震。 (3) 當(dāng)車橋(或車輪)與車橋間的相對(duì)速度過大時(shí)，要求減震器能自動(dòng)加大液流量，使阻尼力始終保持在一定限度之內(nèi)，以避免承受過大的沖擊載荷。 在汽車懸架系統(tǒng)中廣泛采用的是筒式減震器，且在壓縮和伸張行程中均能起減震作用叫雙向作用式減震器，還有采用新式減震器，它包括充氣式減震器和阻力可調(diào)式減震器。 雙向作用筒式減震器工作原理說明：在壓縮行程時(shí)，指汽車車輪移近車身，減震器受壓縮，此時(shí)減震器內(nèi)活塞3向下移動(dòng)?；钊虑皇业娜莘e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。減震器在伸張行程時(shí)，車輪相當(dāng)于遠(yuǎn)離車身，減震器受拉伸。這時(shí)減震器的活塞向上移動(dòng)?；钊锨挥蛪荷?，流通閥8關(guān)閉，上腔內(nèi)的油液推開伸張閥4流入下腔。由于活塞桿的存在，自上腔流來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。這使得減震器的伸張行程產(chǎn)生的阻尼力大于壓縮行程的阻尼力，達(dá)到迅速減震的要求。 減震器的分類 ●材料角度劃分 從產(chǎn)生阻尼材料的角度劃分，減震器主要有液壓和充氣兩種，還有一種可變阻尼的減震器。 (1)液壓式 汽車懸架系統(tǒng)中廣泛采用液力減震器。其原理是，當(dāng)車架與車橋做往復(fù)相對(duì)運(yùn)動(dòng)兒活塞在減震器的缸筒內(nèi)往復(fù)移動(dòng)時(shí)，減震器殼體內(nèi)的油液便反復(fù)地從內(nèi)腔通過一些窄小的孔隙流入另一內(nèi)腔。此時(shí)，液體與內(nèi)壁的摩擦及液體分子的內(nèi)摩擦便形成對(duì)振動(dòng)的阻尼力。 (2)充氣式 充氣式減震器是60年代以來發(fā)展起來的一種新型減震器。其結(jié)構(gòu)特點(diǎn)是在缸筒的下部裝有一個(gè)浮動(dòng)活塞，在浮動(dòng)活塞與缸筒一端形成的一個(gè)密閉氣室種充有高壓氮?dú)?。在浮?dòng)活塞上裝有大斷面的O型密封圈，它把油和氣完全分開。工作活塞上裝有隨其運(yùn)動(dòng)速度大小而改變通道截面積的壓縮閥和伸張閥。當(dāng)車輪上下跳動(dòng)時(shí)，減震器的工作活塞在油液種做往復(fù)運(yùn)動(dòng)，使工作活塞的上腔和下腔之間產(chǎn)生油壓差，壓力油便推開壓縮閥和伸張閥而來回流動(dòng)。由于閥對(duì)壓力油產(chǎn)生較大的阻尼力，使振動(dòng)衰減。 ●結(jié)構(gòu)角度劃分 減震器的結(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)減震器工作速度快時(shí)，阻尼過大會(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，節(jié)流孔開度變大，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。 減震器按其結(jié)構(gòu)，則分為單筒和雙筒兩種?？梢赃M(jìn)一步分為：單筒氣壓減震器、雙筒油壓減震器、雙筒油氣減震器。 (1)雙筒式 指減震器有內(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，因此要通過與外筒進(jìn)行交換來維持內(nèi)筒中油的平衡。所以雙筒減震器中要有四個(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。 (2)單筒式 與雙筒式相比，單筒式減震器結(jié)構(gòu)簡單，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浮動(dòng)活塞的浮動(dòng)來自動(dòng)適應(yīng)之。除了上面所述兩種減震器外，還有阻力可調(diào)式減震器。它可通過外部操作來改變節(jié)流孔的大小。最近的汽車將電子控制式減震器作為標(biāo)準(zhǔn)裝備，通過傳感器檢測行駛狀態(tài)，由計(jì)算機(jī)計(jì)算出最佳阻尼力，使減震器上的阻尼力調(diào)整機(jī)構(gòu)自動(dòng)工作。 筒式減震器的基本介紹 該減震器廣泛應(yīng)用在汽車懸架系統(tǒng)之中，且在壓縮和伸張行程中都能起到減震作用，因此它又叫做雙向作用式減震器。 組件包括：活塞桿、工作缸筒、活塞、伸張閥、儲(chǔ)油缸筒、壓縮閥、補(bǔ)償閥、流通閥、導(dǎo)向座、防塵罩、油封。 在汽車車輪移近車身，減震器受壓縮時(shí)，此時(shí)減震器內(nèi)活塞向下移動(dòng)?；钊虑皇业娜莘e減少，油壓升高，油液流經(jīng)流通閥流到活塞上面的腔室(上腔)。上腔被活塞桿占去了一部分空間，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壓縮閥，流回儲(chǔ)油缸。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。減震器在車輪遠(yuǎn)離車身，減震器受拉伸，這時(shí)減震器的活塞向上移動(dòng)?；钊锨挥蛪荷撸魍ㄩy關(guān)閉，上腔內(nèi)的油液推開伸張閥流入下腔。由于活塞桿的存在，自上腔流來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)油缸中的油液推開補(bǔ)償閥流進(jìn)下腔進(jìn)行補(bǔ)充。由于這些閥的節(jié)流作用，因此對(duì)懸架在做伸張運(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)的常通縫隙和通道截面積總和小于壓縮閥及相應(yīng)常通縫隙通道截面積總和。這使得減震器的伸張行程產(chǎn)生的阻尼力大于壓縮行程的阻尼力，達(dá)到迅速減震的要求。 English translation Shock Absorber Shock Absorber (Absorber), after the shock absorber is mainly used to suppress spring shock absorbers and rebound when the impact from the road surface. When after a rough road, while the shock-absorbing spring can filter road vibration, but the spring itself there will be reciprocated and the shock absorber is used to inhibit this spring jump. Shock absorber is too soft, the body will be jumping up and down, shock absorbers too hard will bring too much resistance, hinder the normal spring work. About the suspension of the conversion process, the hard shock absorber to be matched with the stiffer springs and the spring stiffness and is closely related to vehicle weight and thus heavier vehicles generally use a harder shock absorbers. Cited in contact with the crankshaft shock means for counter crankshaft torsional vibration (ie, crank the ignition cylinder by twisting and impact of the phenomenon). Damper Glossary Shock Absorber (Absorber), after the shock absorber is mainly used to suppress spring shock absorbers and rebound when the impact from the road surface. ? Shock absorber works The suspension system due to the elastic element by the impact of any shock to improve vehicle ride comfort, suspension shock absorbers mounted in parallel with the elastic member for damping vibrations, shock absorbers used in automobile suspension systems are mostly hydraulic damping device, its working principle is that when the frame (or body) and inter-axle vibration occurs relative motion, up and down movement of the piston within the shock absorber, the shock absorber fluid chamber will pass repeatedly from a different chamber pore into the other chamber. In this case internal friction and fluid friction and oil molecules between the cell walls between the damping force of the shock formation, making the car vibration energy into heat oil, then absorbed by the shock absorber circulated into the atmosphere. When oil passage section and other factors constant, the relative velocity damping force with frame and axle (or wheel) between the increase and decrease, and with the oil viscosity is related. Shock absorbers and elastic elements bear the impact and ease the task of damping, the damping force is too large, the elastic suspension will deteriorate, and even the shock absorber connector damage. To adjust the surface due to the elastic element and the damper this contradiction. (1) during the compression stroke (axle and frame close to each other), the smaller the shock absorber damping force, in order to give full play to the elasticity of the elastic element, easing the impact. At this time, the elastic member play a major role. (2) uphold the suspension stroke (axle and frame away from each other), the shock absorber damping force should be large, rapid damping. (3) when the axle (or wheel) and the relative speed between the axle is too large, it is required to automatically increase the shock absorber fluid flow, so that the damping force is always kept within certain limits in order to avoid excessive impact withstand load. In the automotive suspension system is widely used telescopic shock absorber, and is done in the compression stroke and can play a cushioning effect called double-acting shock absorbers, as well as the use of new shock absorbers, which includes inflatable Save shock resistance and adjustable shock absorbers. Double-acting telescopic shock absorber works Description: When the compression stroke, an automobile wheel closer to the body, the shock absorber is compressed, then move down into the damper piston 3. Volume of the piston lower chamber is reduced, oil temperature, oil flow through the circulation flow valve 8 above the piston chamber (upper chamber). The chamber is a piston rod 1 takes up part of the space, thus increasing the chamber volume is less than the lower chamber to reduce the volume, part of the oil so he opened the compression valve 6, back into the storage tank 5. These valves on oil savings formed by compression damping force of the suspension movement. When done damper stroke, the equivalent of the wheel away from the body, shock absorbers under tension. In this case the shock absorber piston moves upward. Piston hydraulic chamber increases, the circulation valve 8 is closed, the upper chamber of the oil valve 4 open stretch into the next chamber. Due to the presence of the piston rod, since the upper chamber to the fluid flow is not sufficient to increase the volume of the lower chamber is filled, dictates the lower chamber to generate a vacuum, then pushed the oil storage tanks in compensating valve 7 flows into the lower cavity supplement. Because these valves throttling the suspension damping to play a role in stretching exercise. Since stretching valve spring stiffness and preload is greater than the compression valve design, under the same pressure, stretching the sum channel load area and the corresponding valve normally-compression valve gap is less than the sum of the cross-sectional area and the corresponding normally-slot channel. This allows the shock absorber damping force is greater than the elongation stroke damping force of the compression stroke, to achieve rapid damping requirements. Damper classification ● Materials division angle From the perspective of damping material division, hydraulic and pneumatic shock absorbers are mainly two types, there is a variable damping shock absorbers. (1) hydraulic Automobile suspension system is widely used in hydraulic shock absorbers. The principle is that when the frame and axle reciprocating piston relative movement of children in the cylinder when the shock absorber reciprocating, oil within the damper housing will be repeated from the other inflow lumen through some narrow pores a lumen. At this time, friction and friction within the liquid molecules of the liquid and the inner wall is formed on the vibration damping force. (2) inflatable Inflatable shock absorbers since the 1960s, developed a new type of shock absorber. The structure is characterized in the lower portion of the cylinder is provided with a floating piston, a sealed chamber in the floating piston and cylinder formed at one end is filled with high-pressure nitrogen species. With large cross-section of the O-ring on the floating piston that is completely separate from the oil and gas. Equipped with its velocity on the size of the working piston and change the channel cross-sectional area of ??the compression valve and valve done. When the wheel up and down, the shock absorber in the working piston reciprocates seed oil, so oil pressure difference generated between the upper chamber and a lower chamber of the working piston, oil pressure will open the valve and compression valve and elongation flow back and forth. Since the valve of the oil pressure have a greater damping force, the vibration damping. ● angle division structure Shock absorber piston rod structure is inserted into the cylinder with a piston in the cylinder filled with oil. Piston orifice, such that the two parts are separated out of the piston space of the oil can complement each other. Damping oil is viscous when produced through the orifice, the orifice the smaller the damping force, the greater the viscosity of the oil, the greater the damping force. If you change the size of the orifice, when the shock absorber to work fast, too much effect on the absorption of damping shocks. Therefore, provided at the outlet of the orifice of a disk-shaped leaf spring valve when the pressure increases, the valve top is open, the orifice opening degree becomes larger, the damping becomes small. Since the piston is a two-way movement, so both sides of the piston valves are equipped with leaf springs, they are called compression valves and valve done. Shock absorber according to their structure, monocular and binocular is divided into two kinds. Can be further divided into: single cylinder gas pressure shock absorbers, hydraulic shock absorbers binoculars, binoculars and gas shock absorbers. (1) binoculars formula It refers to both internal and external shock absorber cylinder, a piston moving the inner cylinder, the piston rod and drawn into the inner tube of oil volume increases and contraction, and therefore with the outer cylinder exchange to maintain the inner tube of oil balance. So binoculars shock absorber have four valves, which in addition to two throttle piston mentioned above, there are mounted on the completion of the exchange interaction flow valve and compensation valve between the inner and outer cylinders. (2) single cylinder Compared with the binocular-type, single tube shock absorbers simple structure, reducing a valve system. It is in the lower part of the cylinder containing a floating piston (referring to the so-called floating piston does not control its movements), the floating piston is formed below a closed chamber, filled with high-pressure nitrogen. Changes in the liquid level of oil out of the piston rod caused by the above-mentioned floating piston will automatically adapt themselves to float. In addition to the above said two damper, there is resistance adjustable shock absorbers. It may be to change the size of the orifice by an external operation. Recent automotive electronic damper control as standard equipment, with state detection by the sensor, the computer calculates the optimal damping force shock absorber damping force adjustment mechanism on the work automatically. Basic introduction of telescopic shock absorber The shock absorber is widely used among automotive suspension systems, and can play a role in damping the compression stroke and done, so it is called double-acting shock absorbers. Assembly comprising: a piston rod, a cylinder barrel, piston, done valves, storage tanks cylinder compression valves, compensation valve, circulation valve, pilot seat, dust cover, oil seal. In the car wheels closer to the body, when the shock absorber is compressed, then moves within the damper piston downward. Volume of the piston lower chamber is reduced, oil temperature, oil flow through the circulation flow valve above the piston chamber (upper chamber). The chamber is a piston rod takes up part of the space, thus increasing the chamber volume is less than the lower chamber to reduce the volume, part of the oil so he opened the compression valve, flow back into the storage tank. These valves on oil savings formed by compression damping force of the suspension movement. In the damper away from the wheel body, by drawing the shock absorber, the shock absorber piston then moves upward. Piston hydraulic chamber increases, the circulation valve is closed, the upper chamber of the oil valve open stretch into the next chamber. Due to the presence of the piston rod, since the upper chamber to the fluid flow is not sufficient to increase the volume of the lower chamber is filled, under the dictates chamber produces a vacuum, then pushed the oil storage tanks in compensation valve flows into the inferior vena supplement . Because these throttling valve, and therefore the suspension damping role to play in doing stretching exercise. Since stretching valve spring stiffness and preload is greater than the compression valve design, under the same pressure, stretching the valve and the corresponding sum of the cross-sectional area less than the normally-channel gap and compression valve and the corresponding sum of the normally-slot channel cross-sectional area. This allows the shock absorber damping force is greater than the elongation stroke damping force of the compression stroke, to achieve rapid damping requirements.