【正文】
等因素激起汽車的振動(dòng),這種由于道路的凸凹不平而引起的沖擊和振動(dòng),通過(guò)車輪傳遞到懸架,然后再由懸架傳遞到車身,從而引起駕駛?cè)藛T及乘座人員的振動(dòng)(當(dāng)然也對(duì)貨物形成沖擊)。懸架系統(tǒng)實(shí)現(xiàn)了車身和車輪之間的彈性連接和彈性支承,因而當(dāng)車輪行駛在凸凹不平的路面而受到復(fù)雜激勵(lì)時(shí),懸架裝置就會(huì)有效地抑制和降低車身和車輪的動(dòng)載,衰減車身和車輪的振動(dòng),從而保證車輛行駛的舒適性和安全性。國(guó)外先進(jìn)工業(yè)化國(guó)家減振器的發(fā)展也經(jīng)歷了從搖臂式液壓減振器到筒式液壓減振 器(單作用式筒式液壓減振器和雙作用式液壓減振器)再到充氣式液壓減振器(單筒充氣式液壓減振器和雙筒充氣式液壓減振器)和阻力可調(diào)式液壓減振器(手動(dòng)調(diào)節(jié)或電動(dòng)調(diào)節(jié))的過(guò)程,現(xiàn)在已研制出用電子系統(tǒng)控制的自適應(yīng)式液壓減振器(可根據(jù)激振頻率和振幅來(lái)調(diào)節(jié)阻尼的減振器),這種減振器可根據(jù)不同路面條件和不同的行駛要求,通過(guò)多級(jí)匹配與調(diào)節(jié),從而在特性曲線族中,獲得一條令人相當(dāng)滿意的特性曲線,從而優(yōu)化和提高車輛行駛的舒適性(平順性)和安全性,為底盤(pán)的優(yōu)化展示出新的前景。目前,國(guó)外先進(jìn)工業(yè)化國(guó)家液壓減振器正朝著充氣式減振器、可調(diào)減振器(如載荷感應(yīng)式、位移依存式、位置依存式等)及自適應(yīng)減振器(如電流變減振器、磁流變減振器等)的方向發(fā)展。雙筒充氣液壓減振器的理論和時(shí)間在我國(guó)目前仍處于起步階段,其理論研究及生產(chǎn)實(shí)踐同國(guó)外先進(jìn)工業(yè)國(guó)家相比較有較大差距,有待各科研機(jī)構(gòu),大專院校及企業(yè)作進(jìn)一步 的研究開(kāi)發(fā)工作,以縮短同國(guó)外同行的差距。 (4)減振器試驗(yàn)臺(tái)測(cè)控系統(tǒng)軟硬件設(shè)計(jì)。 圖 試驗(yàn)臺(tái)結(jié)構(gòu)簡(jiǎn)圖 1位移計(jì) 9 這種試驗(yàn)臺(tái)結(jié)構(gòu)簡(jiǎn)單,成本較低,占地面積小。測(cè)試信號(hào)作為輸入信號(hào)進(jìn)入系統(tǒng)后 ,經(jīng)過(guò)一系列變換轉(zhuǎn)變?yōu)檩敵鲂盘?hào),同時(shí)還包含了兩方面的誤差:一是輸入信號(hào)的誤差經(jīng)系統(tǒng)傳遞函數(shù)轉(zhuǎn)換而來(lái);二是系統(tǒng)中 本科生畢業(yè)設(shè)計(jì)(論文) 8 硬件本身引起的制造精度或轉(zhuǎn)換精度引起的誤差。本文所研究的對(duì)象,通用減振器試驗(yàn)臺(tái)的激勵(lì)部分就是采用曲柄 — 連桿結(jié)構(gòu)。 電動(dòng)機(jī)類型的選擇要從負(fù)載的要求出發(fā),考慮工作條件、負(fù)載性質(zhì)生產(chǎn)工藝、供電情況等。布置時(shí)可以采用圓錐齒輪或圓錐 圓柱齒輪減速器。 曲柄連桿滑塊機(jī)構(gòu)的設(shè)計(jì)是實(shí)驗(yàn)臺(tái)關(guān)鍵的環(huán)節(jié),它既是傳力件,又是運(yùn)動(dòng)件,因此其工作可靠性就決定了實(shí)驗(yàn)臺(tái)工作的可靠性, 如圖 所示。 圖 曲柄 連桿機(jī)構(gòu)可簡(jiǎn)化為圖 模型。 圖 曲柄 連桿 雙平衡塊力學(xué)模型 下面對(duì)此系統(tǒng)慣性作一分析 : x向慣性力之和 ∑ EFx =m1 xd1 +m2 xd2 +m3 xd3 +m4 xd4 (45) y向慣性力之和 ∑ EFy =m1 yd1 +m2 yd2 +m3 yd3 +m4 yd4 (46) 其中 x1 =hcosXt x2 =hcosXt+lcosU x3 =HcosXt x4 =hcosXtLcosU y1 =hsinXt y2 =0 y3 =HsinXt y4 =hsinXt+LsinU 幾何條件 本科生畢業(yè)設(shè)計(jì)(論文) 15 sinU= lh sinXt cosU= Usin1 2? 41 ( lh ) 2 (1cos2 Xt) 要使整體慣性力平衡 ,則 ∑ EFx =0 (47) ∑ EFY =0 (48) 把上述坐標(biāo)及幾何條件代入式 (7)、式 (8),并忽略二階小量 O( lh )2 ,可得 x向 (m1 h+m2 hm3 H+m4 h)X2 cosXt=0 (49) y向 [m1 hm3 H+m4 h(1+ lL )]X2 sinXt=0 (410) 故有 m3 H=(m1 +m2 +m3 )h (411) m4 L=m2 l (412) 因此 ,只要選擇 (m3 ,H)和 (m4 ,L)使之滿足式 (11)、式 (12)即可使系統(tǒng)整體慣性力達(dá)到平衡。即只要在 m1 的對(duì)稱位置加一質(zhì)量為 kg的平衡塊即可消除 y 向慣性力。 實(shí)驗(yàn)臺(tái)在工作的工程中,電動(dòng)機(jī)所受載荷為中等沖擊載荷。見(jiàn)圖 61。 顯然機(jī) 構(gòu)誤差包括位移誤差、速度誤差和相位誤差 ,并且誤差隨曲桿比變化而有所變化。以一個(gè)拉壓復(fù)合彈簧實(shí)現(xiàn)正反載荷的交變作用,由于彈簧是軟連接,為防止運(yùn)動(dòng)方向產(chǎn)生改變,采 用導(dǎo)軌對(duì)機(jī)構(gòu)的運(yùn)動(dòng)加以限制,來(lái)保證始終做垂直往復(fù)運(yùn)動(dòng)。 大學(xué)學(xué)習(xí)生活中, XXXX 學(xué)院各位老師在學(xué)業(yè)上給我的指導(dǎo),尤其是各位老師一絲不茍的治學(xué)風(fēng)范對(duì)我的影響很大;在 畢業(yè)設(shè)計(jì) 過(guò)程中,各位老 師給予了大力的支持和幫助,并就 設(shè)計(jì) 中的部分問(wèn)題和處理方法共同進(jìn)行了有益的探討,在此一并向他們致以誠(chéng)摯的謝意!在此也對(duì)審閱和評(píng)議本 畢業(yè)設(shè)計(jì) 及答辯老師和教授致以崇高的敬意和誠(chéng)摯的感謝! 最后,對(duì)在大學(xué)期間關(guān)心與幫助過(guò)我的其他所有人表示感謝! 、 本科生畢業(yè)設(shè)計(jì)(論文) 25 附錄 一 Hydraulic shock absorber test bench and applied research on the transformation Preface Hydraulic shock absorber, vehicle suspension system ponents in the main damping, The quality of their performance is directly related to vehicle safety and fort. Hydraulic shock absorber by the performance of the main characteristics that, Characteristics of the shock absorber shock absorber means with relative movement of the displacement or relative velocity with the corresponding resistance resulting from the work of the relationship between, The relationship between these two indicator known as the shock absorber characteristics and speed characteristics. Shock absorber to improve the performance, To ensure the quality, In addition to advanced design, production process, Means of modern management, As well as advanced test and test equipmentTo detect characteristics of the shock absorber with the design requirements, Commonly used testbed general hydraulic shock absorber for dualcolumn structure, The lower cost structure, Small footprint. Jiangxi, a shock absorber in accordance with the requirements of the production plant, In its original twocolumn structure of the hydraulic shock absorber on the basis of testbed transformation. The redesign of the puter detection system, And the application of the shock absorber shock absorber test bench analysis of the quality of the process methodology. This article describes the main technical. 1 Testbed design of the puter detection system 1 ? 1 System Components Imposed on the shock absorber test bed approach is inspired in its one end to impose similar to simple harmonic movement, In this study, using a simple structure, Easy to implement on the heart of the crank linkage system as an incentive. According to the original testbed instability detection system performance, Graphic distortion characteristics and the speed the more serious the situation is not convenient, The redesign of the puter detection system, System Components Figure 1, The system 本科生畢業(yè)設(shè)計(jì)(論文) 26 uses microputer as the main monitoring and control machines, Optional PS2112 16 Road, A / D conversion board and travel as a shock absorber damping force of the two ADC signal, The converter board is programmable interface board, Its resolution of 12, Conversion time of about 25μs, Of 5 ~ +5 V analog signal for analogtodigital conversion, Systematic error of less than 0 ? 1%, to ensure that the detection accuracy. Shock absorber damping force sensor using strain la (pressure) force sensor, Can be used for different force sensor to change the measuring range, Can be used for different force sensor to change the measuring range, Strain gauge used for the preamplifier, Output of 5 ~ +5 V, Measuring accuracy of less than 0 ? 5%. Damper displacement sensor using a differential transformer type displacement sensor, For different displacement sensor can change the maximum range, Output voltage of 5 ~ +5 V, Determination of the accuracy of displacement is less than 0 ? 5%, FM is used in a certain scope for regulating frequency vibration table, Excitation in order to adjust the speed, you can both by regulating the shaking table of the relative position of flange exciting journey to change in order