【正文】 人類技術進步還是比較快的。 電子液壓動力轉向系統(tǒng) 雖然采用了電能作為動力源，但是仍然保留有液壓動力傳遞系統(tǒng)，因此電 子 液壓助力轉向系統(tǒng)仍然具有一些機械液壓助力轉向系統(tǒng)缺點，例如系統(tǒng)結構復雜，以及液壓管路有泄漏的可能等問題。 綜上所述，總結出電子液壓助力轉向系統(tǒng)：由電動機直接帶動液壓泵工作。 工作順序：蓄電池 電動機 液壓泵 助力到轉向機構 特點：有液壓泵，液壓油，無皮帶，結構緊湊，壓力穩(wěn)定，助力力矩好控制，較容易實現(xiàn)低速方向輕，高速時方向重。 39 致 謝 本次畢業(yè)設計雖然僅僅經(jīng)歷了短暫的三個月，但是它濃縮了大學四年學習的全過程，體現(xiàn)了我們對所學知識的掌握和領悟程度。由于我們是第一次進行整體性地設計，不可避免地碰到了許多困難，有時甚至會感到無法下手。無論碰到什么樣的 業(yè)設計期間，老師給予了極大的關心和幫助：無論是在轉向器實物尋找和拆裝、疑難解答還是在圖紙繪制方面，指導老師以嚴謹求實的治學態(tài)度給我們留困難，我都沒有退縮，憑借著一股求知的熱情，再加上指導老師的幫助，然后再回到書本攻克一個又一個的難題，最終圓滿地完成了本次設計 。 首先我要向指導老師 致以最誠摯的謝意！畢 下了深刻的印象，成為我們現(xiàn)在以至將來走上工作崗位學習的楷模。 其次，我要感謝實驗室老師所提供的物質條件，保證了畢業(yè)設計的順利進行。在畢業(yè)設計過程中，有很多同學給 的大力支持，為我們提供的良好的畢業(yè)設計環(huán)境。在汽車實驗室的畢業(yè)設計期間，我們充分使用了實驗室 予了我寶貴意見，在此一并感謝！ 通過這次設計，我學到了很多有用的東西，首先從大的方面來講，設計過程就是把四年所學知識作了全面的串接和溫習過程，對以前許多模糊之處有了重新的認識。 我的畢業(yè)設計課題是汽車 動力 轉向系的設計，開始做時走了不少彎路， 鑒于動力轉向這塊，大體上相同，都是泛泛而談，涉及到的細節(jié)不多，甚至有許多錯誤，不同的人編寫的書，有許多地方出入很大，不知信誰的，又沒有標準，導致盲目地摸索，費了許多時間。 這次我的最大收獲是明白了無論做什么事件，多要有一個好的可行性思路，按照大體框架，做起來才比較得手，對“良好的開端是成功的一半”有了深刻理解。它對我以后的工作也墊定了良好的基礎，對其有著很多的啟示和借鑒作用。 最后再次感謝身邊的老師和同學，在我大學四年的求學生涯以及此時畢業(yè)設計之際所給予的一貫支持和鼓勵！ 在我結束畢業(yè)設計的同時，也結束了我的 大學生活。這意味著我進入了人生新的起點，我會用我在學校所學到的知識在嶄新的 40 生活中不斷進取，發(fā)奮圖強。用我的事業(yè)成就來報答學校和老師對我的栽培，回報社會對我的關愛！ 41 參 考 文 獻 [19] 毛彩云，吳暮春，柯松 .汽車轉向系統(tǒng)的發(fā)展 [J].科普園， . Visafree policy brings Chengdu biz, tourism boost. Making national headlines several times, Chengdu39。s 72hour visafree policy has attracted wide attention from both Chinese and foreign experts and businessmen since it took effect on Sept 1 last year. The program permits citizens from 51 countries and regions including the United States, Australia, Canada and Japan who have valid visas and flight tickets to a third country to spend three days in the city. The capital of Sichuan province is the first city in the western region of China to offer foreign tourists a threeday visa and the fourth nationwide to adopt the policy following Shanghai, Beijing and Guangzhou. Li Zhiyong, deputy dean of the tourism institute at Sichuan University, said the move contributes to a large increase in the number of overseas tourists [1] 關文達 .汽車構造 [M].北京：機械工業(yè)出版社， 2021. [2] 胡建軍，李彤 .汽車轉向技術進展分析 [J].液壓與氣動， . [3] 高建春，朱賢達 .齒輪式轉向機構 [J].上海應用技術學院學報， . [4] 新浪汽車 .淺談汽車轉向系統(tǒng) [OL]. . [5] 馮櫻 .汽車電子控制式電動助力轉向系統(tǒng)的發(fā)展 [J].湖北汽車工業(yè)學院學報， 2021. [6] 王望予 .汽車設計 [M].北京：機械工業(yè)出版社， 2021. [7] 濮良貴、紀名剛 .機械設計 [M].北京：高等教育出版社， 2021. [8] 姚明龍、王福林 .車輛轉向梯形優(yōu)化設計及其求解方法的研究 [J].機械設計與制造 .. [9] 黃鶴輝、陳晨 .整體式轉向梯形機構優(yōu)化設計 MATLAB 程序 [J].廣西機械 .. [10] 申永勝 .機械原理教程 [M].北京：清華大學出版社， . [11] 徐灝 .機械設計手冊 [M].北京：機械工業(yè)出版社， 1992. [12] 畢大寧 . 汽車轉閥式動力轉向器的設計與應用 [M].北京：人民交通出版社 ,1998. [13] 余志生 .汽車理論 [M].北京：機械工業(yè)出版社， 2021. [14] 季學武等 . 動力轉向系統(tǒng)的發(fā)展與節(jié)能 [J].世界汽車 , . [15] 季學武等 . 動力轉向系統(tǒng)的發(fā)展與節(jié)能 [J].世界汽車 , . [16] 陳家瑞 .汽車構造下冊 [M].北京：人民交通出版社， 2021. [17] 馮超等 .汽車工 程手冊 [M].北京：人民交通出版社， 2021. [18] 劉維信 .汽車設計 [M].北京：清華大學出版社， 2021. 42 and raises the city39。s level of internationalization. The policy will also bring direct economic revenue, Li said. Chengdu has many cultural legacies and is also a paradise for panda lovers with the world39。s largest breeding and research center. Three d ays are long enough for foreign visitors to visit those iconic tourist spots, he noted. The city is home to the remains of the Jin sha civilization that dates back more than 3,000 years as well as the Qing cheng Mountains and the Du jiang yan irrigation system. Qing cheng has long been recognized as the birthplace of Taoism, China39。s ancient indigenous religion, while Du jiang yan is considered to be the oldest functioning watercontrol project in the world. Chengdu ranked third in tourist facilities, management and services among 60 Chinese cities in a customer satisfaction survey released last year . But, Li added that efforts are still needed to develop more tourism products, improve English services and provide accurate translation of traff ic signs and scenic billboards. Zhao Yun, chairwoman of British Chamber of Commerce Southwest China, told Ch ina Daily that his colleagues found the policy very convenient. A British client once flew here and stayed for just one day to check her ordered goods, she said. Zhao was born in Shanxi province, but she has lived in Chengdu for more than 10 years. My life was like a running race moving from place to place. I also lived in Beijing and Shanghai before, she said. But Chengdu is a place that you never want to leave once settling down. It is now my second hometown, she said. If the environment is further improved, the city will attract more people to visit and live, with the 72hour visafree policy and pelling conditions in transportation, culture, climate and cuisine, he said. Foreigners also gave positive feedback on the policy. A spokesman from Dell Inc said the pany has a global hub of operation in Chengdu, so the threeday visa has an immediate and positive influence on the pany39。s business development. Rudy Buttignol, president of the public broadcasting pany in British Columbia, Canada, said his work requires frequent travel to Chengdu and the policy makes the trips easier. Data from the city39。s public security bureau shows some 100 foreign visitors enjoyed the 72hour policy by the end of March, most of them from the United States, the United Kingdom and Germany. Chengdu also reported robust growth in its overall tourist industry last year. Official statistics show that it received some 150 million tourists last year, an increase of 28 percent from 2021. Around million came from abr oad, an increase of 12 percent. Total revenue from tourism surpassed 133 billion yuan ($). During his visit to Kazakhstan in September, Chinese President Xi Jinping proposed that China and Central Asia join hands to build a Silk Road economic belt to boost cooperation. The idea has been widely echoed in Central Asian countries, being an encouraging blueprint for Chinese areas along the Silk Road that has