本文關(guān)鍵詞：復(fù)雜杯桿件溫冷聯(lián)合精密成形數(shù)值模擬及工藝優(yōu)化　出處：《長春工業(yè)大學(xué)》2016年碩士論文　論文類型：學(xué)位論文

  更多相關(guān)文章： 復(fù)雜杯桿零件 溫冷聯(lián)合工藝 數(shù)值模擬 模具磨損 參數(shù)優(yōu)化

【摘要】：隨著汽車行業(yè)的快速發(fā)展和日益激烈的市場競爭,人們對汽車的安全性能及舒適性能要求越來越高。汽車轉(zhuǎn)向系統(tǒng)的性能好壞直接影響整車性能,汽車轉(zhuǎn)向螺桿作為汽車轉(zhuǎn)向系統(tǒng)的一個重要零部件,其性能的好壞同樣直接影響轉(zhuǎn)向系統(tǒng)可靠性,進(jìn)而影響整車性能。汽車轉(zhuǎn)向螺桿是典型杯桿型零件,其形狀復(fù)雜,精度要求高,可通過溫冷聯(lián)合擠壓成形工藝達(dá)到其形狀和精度要求。本文通過利用有限元數(shù)值模擬來分析汽車轉(zhuǎn)向螺桿在溫冷聯(lián)合技術(shù)下的成形,對汽車轉(zhuǎn)向螺桿的成形工藝進(jìn)行比較,并確定成形工藝方案,同時對溫擠壓凹模進(jìn)行磨損分析。首先,對汽車轉(zhuǎn)向螺桿制定兩種可行的溫冷結(jié)合工藝方案,即多工序復(fù)合擠壓成形和兩工序復(fù)合擠壓成形(杯桿復(fù)合成形工藝)。利用有限元模擬軟件Deform對兩種工藝方案進(jìn)行熱力耦合數(shù)值模擬,獲得成形過程中每道工序的成形時間-載荷曲線圖、速度場分布矢量圖、并觀察成形過程中出現(xiàn)的問題,以此作為比較標(biāo)準(zhǔn),對兩種工藝方案進(jìn)行對比,最終選擇兩工序復(fù)合擠壓作為成形工藝。其次,在溫擠壓內(nèi)孔工序時,磨損是影響凹模壽命的主要因素。結(jié)合正交試驗(yàn)法和基于Archard磨損模型下的有限元數(shù)值模擬法,對溫擠壓凹模磨損進(jìn)行分析,選擇凹模入口圓角半徑r、模具初始溫度t、模具初始硬度HRC,摩擦因子m為影響凹模磨損的四個參數(shù)因素,并選擇不同因素的4個水平,確定了L16(45)正交試驗(yàn)方案,通過極差分析和方差分析得出凹模入口圓角半徑2mm、模具初始溫度350℃、模具初始硬度HRC55,摩擦因子0.2為使凹模磨損量最小的最優(yōu)組合,對最優(yōu)工藝參數(shù)組合進(jìn)行建模、數(shù)值模擬分析,得出凹模磨損量,進(jìn)行模具壽命的預(yù)測。最后,由于智能算法的推廣應(yīng)用和正交試驗(yàn)分析的局部性問題。使用影響凹模磨損的四個參數(shù)組合與在有限元數(shù)值模擬下的模具磨損量組成32組數(shù)據(jù)樣本,訓(xùn)練BP神經(jīng)網(wǎng)絡(luò),建立凹模入口圓角半徑r、模具初始溫度t、模具初始硬度HRC,摩擦因子m與凹模磨損量之間的映射關(guān)系,以溫擠壓凹模磨損量為目標(biāo)函數(shù),通過遺傳算法對四個影響因素進(jìn)行組合優(yōu)化,使凹模磨損量最小。研究結(jié)果顯示:采用本方法優(yōu)化參數(shù)得出的最大磨損量與正交實(shí)驗(yàn)法相比降低了12.35%,說明該設(shè)計方法是可行的。
[Abstract]:With the rapid development of the automobile industry and the increasingly fierce market competition, people have higher and higher requirements for the safety and comfort performance of the vehicle. The performance of the automobile steering system has a direct impact on the performance of the whole vehicle. As an important part of automobile steering system, the performance of steering screw also directly affects the reliability of steering system and further affects the performance of the whole vehicle. The steering screw is a typical cup rod part. The shape and precision can be achieved by the combined extrusion process of temperature and cold. In this paper, finite element numerical simulation is used to analyze the forming of automobile steering screw under the combined technology of temperature and cold. The forming process of automobile steering screw is compared, and the forming process scheme is determined. At the same time, the wear analysis of warm extrusion die is carried out. Firstly, two feasible warm and cold combination process schemes are made for automobile steering screw. That is, multi-process composite extrusion forming and two-process composite extrusion forming (cup bar composite forming process). The thermo-mechanical coupling numerical simulation of the two process schemes is carried out by using finite element simulation software Deform. The forming time-load curve and velocity field distribution vector diagram of each process are obtained, and the problems in the forming process are observed, which is taken as the comparison standard to compare the two process schemes. Finally, two processes of composite extrusion as the forming process. Secondly, in the warm extrusion process of the inner hole. Wear is the main factor affecting die life. Combined with orthogonal test method and finite element numerical simulation method based on Archard wear model, die wear of warm extrusion die is analyzed. Four parameter factors affecting the wear of the die are selected: the inlet radius r, the initial temperature t, the initial hardness HRC, the friction factor m, and the four levels of different factors. L1645) orthogonal test scheme was determined. By means of range analysis and variance analysis, the inlet radius of the die was 2 mm, the initial temperature of the die was 350 鈩，

本文編號：1439576