【正文】 monitor traffic and makeshift will not be confused. Automotive automatic transmission has three mon forms: They are sweet hydraulic automatic transmission (AT), mechanical stepless automatic transmission (CVT), electronically controlled automatic transmission machinery (AMT). At present, the widespread use of the car is AT, AT bee almost synonymous with automatic transmission. AT by hydraulic Torque, plaary gears and hydraulic control system, hydraulic and transmission gear bination approach to achieve the speed change moment. One hydraulic Torque AT is the most important ponents, which pumps round, and the turboround lead, and other ponents, both torque transmission and clutch. The automatic transmission gear In general, the automatic transmission into gear P, R, N, D, 2,1, or L, and so on. P (Parking): used for parking purposes, it is the use of mechanical locking device to the rotating part of the car so that the vehicle can not move. When the car need to stay in a fixed position for a longer period, or after leaving the vehicle to stop *, players should pull brake lever and promote the P position. It should be noted that: The vehicle must be pletely stopped before they can block the use of P, otherwise automatic 30 transmission will be part of the mechanical damage. In addition, automatic transmission cars [neutral start switch devices, motor vehicles can only be made in the P or N in order to start the engine block, and other gear in order to avoid misuse of the vehicle suddenly starts channeling ago. R (Reverse): reverse gear, the vehicle reversed. Usually allocated according to the insurance button on a post in order to lever will be moved to the r block. It should be noted that: when the vehicle has not yet es to a plete halt, must not be forced to r block, or transmission will be seriously damaged. N (Neutral): neutral. Lever will be placed in N gear, engine and transmission between the separation of power has been cut off. As a brief stopover can be placed lever and pull off the hand brake rod, the right foot can be removed from the brake pedal a little rest. D (Drive): forward gear, with road traffic in general. Since there are different models of the designs, D from a general ward off high block or 2 off high gear and as a result of changes in speed and load automatically shift. Lever will be placed in the D block, at the wheel speed to control the pace as long as the control pedal it. 2 (Second Gear): 1 block to block progress, but the only transmission in a block, block 2 between the change will not jump to block 3 and block 4. 2 will be placed on the gear lever, the car will be a starting block, when the rate increases will automatically switch to a block. 2 can be used to block the upper and lower slopes, the benefits of this section of the block wh en climbing or down ramp, the vehicle will maintain a stable block in 1 or 2 position block, will not load on the ramp or not the speed Balanced, nonstop to block transmission. Dropin slope, the use of lowspeed engine braking for the resistance and will not make the car more the faster the line. 1 (First Gear): 1 block progress is blocked, but the only transmission in 31 a block to work. Can not transform into other gear. Use it in a serious traffic congestion and a greater angle of the slope on the best to perform their functions. On the slopes or under the slope, they can make full use of the car39。這樣，工作液壓油進(jìn)入相應(yīng)的執(zhí)行元件，使離合器結(jié)合或分離，制動(dòng)器制動(dòng)或松開(kāi)，控制行星齒輪變速器的升擋或降擋，從而實(shí)現(xiàn)自動(dòng)變速。駕駛員通過(guò)自動(dòng)變速器的操縱手柄改變閥板內(nèi)的手動(dòng)閥位置，控制系統(tǒng)根據(jù)手動(dòng)閥的位置及節(jié)氣門(mén)開(kāi)度、車(chē)速、控制開(kāi)關(guān)的狀態(tài)等因素，利用液壓自動(dòng)控制原理或電子自動(dòng)控制原理，按照一定的規(guī)律控制齒輪變速器中的換擋執(zhí)行機(jī)構(gòu)的工作，實(shí)現(xiàn)自動(dòng)換擋。 液壓控制系統(tǒng)是由閥體和各種控制閥及油路所組成的，閥門(mén)和油路設(shè)置在一個(gè)板塊內(nèi)，稱(chēng)為閥體總成。在發(fā)動(dòng)機(jī)運(yùn)轉(zhuǎn)時(shí)，不論汽車(chē)是否行駛，油泵都在運(yùn)轉(zhuǎn)，為自動(dòng)變速器中的變矩器、換擋執(zhí)行機(jī)構(gòu)、自動(dòng)換擋控制系統(tǒng)部分提供一定油壓的液壓油。制動(dòng)器的作用是將行星齒輪機(jī)構(gòu)中的某個(gè)元件抱住，使之不動(dòng)。行星齒輪機(jī)構(gòu)是實(shí)現(xiàn)變速的機(jī)構(gòu)，速比的改變是通過(guò)以不同的元件作主動(dòng)件和限制不同元件的運(yùn)動(dòng)而實(shí)現(xiàn)的。采用普通齒輪式的變速器，由于尺寸較大，最大傳動(dòng)比較小，只有少數(shù)車(chē)型采用。上斜坡或下斜坡時(shí)，可充分利用汽車(chē)發(fā)動(dòng)機(jī)的扭力。在落斜坡時(shí)，利用發(fā)動(dòng)機(jī)低轉(zhuǎn)速的阻力作制動(dòng)，也不會(huì)令車(chē)子越行越快。將撥桿放置在 “D” 擋上，駕車(chē)者控制車(chē)速快慢只要控制好油門(mén)踏板就可以了。將撥桿置于 “N” 擋上，發(fā)動(dòng)機(jī)與變速器之間的動(dòng)力已經(jīng)切斷分離。 R(Reverse)：倒擋，車(chē)輛倒后之用。 P(Parking)：用作停車(chē)之用，它是利用機(jī)械裝置去鎖緊汽車(chē)的轉(zhuǎn)動(dòng)部分，使汽車(chē)不能移動(dòng)。目前轎車(chē)普遍使用的是 AT， AT 幾乎成為自動(dòng)變速器的代名詞。 席振鵬老師對(duì)我的論文研究工作提出了許多寶貴意見(jiàn)，在此向他們表示衷心的感謝！ 陳建國(guó)師兄、葛寅山師弟對(duì)論文的研究工作也給予了很大的支持，在此向他們表示最誠(chéng)摯的謝意！ 焉得諼草，言樹(shù)之背，非常感謝我的爸爸媽媽?zhuān)麄冇脺嘏碾p肩呵護(hù)我，給了我自由的成長(zhǎng)空間，一直支持我的決定，我深深?lèi)?ài)著他們。從論文的選題、研究、撰寫(xiě)到定稿，無(wú)不滲透著導(dǎo)師的心血郭秦老師高尚的品德、淵博的學(xué)識(shí)、深邃的思想、嚴(yán)謹(jǐn)?shù)闹螌W(xué)態(tài)度、精益求精的工作作風(fēng)、開(kāi)拓的創(chuàng)新思維、教書(shū)育人的責(zé)任心都給我留下了深刻的印象，將使我受益匪淺，終生難忘。優(yōu)化過(guò)程中考慮了各個(gè)檔位的使用頻度，并根據(jù)標(biāo)準(zhǔn)行駛工況計(jì)算出了各個(gè)頻度的數(shù)值。并分別分析了其工作原理及各個(gè)檔位的動(dòng)力傳遞路線，計(jì)算了其傳動(dòng)比。 21 結(jié) 論 AT 是自動(dòng)變速傳動(dòng)技術(shù)中應(yīng)用最為廣泛的結(jié)構(gòu)形式。 本章小結(jié) 本章用優(yōu)化軟件 Matlab 對(duì) AT 各個(gè)檔位行星排的齒輪參數(shù)進(jìn)行了參數(shù)優(yōu)化。 優(yōu)化結(jié)果 本文優(yōu)化的結(jié)果如表所示。此外可用于齒輪優(yōu)化設(shè)計(jì)的軟件還有： Mathcad 、 頻 域 仿 真 軟 件 FREDOMSIM 和 EDEN （ Electrical Design Enviorment）等等。 優(yōu)化軟件 齒輪參數(shù)的優(yōu)化設(shè)計(jì)通常是借助于軟件來(lái)實(shí)現(xiàn)。而對(duì)于變速器而言，行星排齒輪的齒數(shù)和模數(shù)是固定的，因此這里不把齒數(shù)和模數(shù)選為設(shè)計(jì)變量。 η η η η4 分別為變速器工作在一檔、二檔 、直接擋和四檔時(shí)，行星排的傳動(dòng)效率。結(jié)果顯示：同一行星排的嚙合效率和整體效率升速傳動(dòng)比減速傳動(dòng)時(shí)要高。可以看出，一檔的效率要高于二檔時(shí)的效率，這與用本文所推導(dǎo)公式計(jì)算的結(jié)果一致，說(shuō)明本文的計(jì)算結(jié)果是合理的。 一檔 二檔 三檔 四檔 嚙合效率 軸承效率 液力損失 總效率 行星排各個(gè)檔位的傳動(dòng)效率 由計(jì)算結(jié)果可以看出：自動(dòng)變速器在不同檔位時(shí)的效率不相等。 二檔時(shí)的輪齒嚙合效率為 η th=1+η 1η 2η 3η 4I0／ 1+I0= I0=(Z4/Z5+Z4/Z1)/(Z4/Z5+1)=(63/29+63/23)/(63/29+1)= 15 加速傳動(dòng) 四檔時(shí)的效率 四檔即超速檔是行星排輸出軸轉(zhuǎn)速高于輸入軸轉(zhuǎn)速的升速傳動(dòng)。 外嚙合斜齒輪傳動(dòng)在升速時(shí)基本嚙合效率的計(jì)算式： ? ? ? ?? ? ? ?11s i n/1/11 ????? ??? ftaRR fZZtZntrapgpGpnpo ??? ??? 外嚙合斜齒輪傳動(dòng)在減速時(shí)基本嚙合效率的計(jì)算式： 14 ? ? ? ?? ? ? ?111211 s i n/1/11 ????? ??? ftaRR fZZtZntrapgno ??? ??? 各檔位 傳動(dòng)效率分析 減速傳動(dòng) 一、二檔時(shí)的效率 對(duì)變速器中行星排的效率進(jìn)行分析需要考慮幾個(gè)方面：行星排各工作齒輪之間的嚙合效率；工作軸承的效率；以及液力損失對(duì)效率的影響。因此，采用端面參數(shù)時(shí)，一對(duì)斜齒輪間的基本嚙合效率可由距基準(zhǔn)面（設(shè)斜齒輪寬度方 向上的中截面為基準(zhǔn)面）任意距離的無(wú)限薄直齒輪的相應(yīng)表達(dá)式通過(guò)積分而得到，以回避直接分析的困難。其中兩個(gè)前進(jìn)檔是行星排輸出軸轉(zhuǎn)速低于輸入軸轉(zhuǎn)速的減速傳動(dòng)（即 1 檔和 2 檔），直接檔是輸入軸轉(zhuǎn)速和輸出