摘 要

閉塞式精鍛工藝屬于金屬塑性加工的先進(jìn)工藝，齒輪精鍛就是通過精密鍛造直接獲得完整齒形，且齒面不需或僅需少許精加工即可使用的齒輪制造技術(shù)。它有效地改善了齒輪的組織和性能。精鍛使金屬三向受壓，晶粒及組織變細(xì)，致密度提高，微觀缺陷減少；精鍛還使金屬流線沿齒形連續(xù)均勻分布，提高了齒輪的機(jī)械性能。且精鍛齒輪的精度能達(dá)到精密級(jí)公差、余量標(biāo)準(zhǔn)，使得工件不需或者只需少量精加工就可進(jìn)行熱處理或直接使用，提高了生產(chǎn)效率及材料利用率，降低了生產(chǎn)成本，因此大大提高了齒輪的市場(chǎng)競爭能力。
冷精鍛通常指的是在室溫下對(duì)毛坯進(jìn)行精密鍛造。采用冷精鍛工藝的優(yōu)點(diǎn)是:可以降低原材料消耗，材料利用率高，鍛壓后的金屬材料晶粒組織更加細(xì)小而致密，金屬流線不被切斷加上所產(chǎn)生的加工硬化特征，可使鍛件的強(qiáng)度大為提高，可以獲得較高的尺寸精度和較高的表面光潔度。但其缺點(diǎn)是:成形單位壓力大，模具易磨損，損壞，因此要求模具材料好;對(duì)成形設(shè)備要求較高，噸位要大，除要求鍛壓設(shè)備應(yīng)有較大的強(qiáng)度以外，還要求較好的剛度;且通常要在鍛壓前對(duì)坯料做磷化皂化處理，且處理的好壞直接關(guān)系到后序鍛造的效果。本課題主要是應(yīng)用模擬軟件對(duì)不同的情況進(jìn)行模擬分析，從材料損傷因子，充填效果方面來確定成型工藝。


關(guān)鍵詞：半軸齒輪，閉塞式冷精鍛，模擬分析，損傷因子，模具設(shè)計(jì)













ABSTRACT

Enclosed-die forging process is one of the advanced processes in the field of metal plasticity shaping. Full gear-shape can be obtained through precision forging process, and the tooth need no or little precision machining only. The structure and performance of gear can be improved effectively through this process. The process can make material receiving pressures in three directions. So it can attenuate crystal grains, improve the density and decrease microcosmic flaws. It can also make metallic streamline on teeth more continuous and symmetrical, and lead to the improvement of mechanical performance of gear. The precision of gear can reach very high level, resulting in that the workpiece needs no or little machining only to be heat treated or used directly. The process improves producing efficiency and use ratio of materials, decreases producing cost. Therefore the competing ability of gears is improved greatly。
Cold precision forging usually refers to the right rough at room temperature for precision forging. With cold precision forging of the advantages are: lower raw material consumption, high utilization of materials, forging the metal material grain organizations more small and compact, metal flow is not cut off the line with the characteristics of the work-hardening, forging will Greatly increased the intensity will be entitled to a higher dimensional accuracy and a high surface finish. But its disadvantages are: forming load is large, die easy to be damage, die material called good，higher on the forming equipment, and tonnage should be large,；with the exception of forging equipment requirements should be greater intensity, also demanded better stiffness and usually do saponification and phosphating before forging, and handling will have a direct relationship to the sequence after forging results. The main issue is the application of a simulation software to simulate the different circumstances of the material damage factor, to determine the effect of filling process.


Key words： half axle gear, enclosed-die cold precision forging, simulation analysis,
damage, die design

目 錄

中文摘要 Ⅰ
ABSTRACT Ⅱ
1緒論 1
1.1 引言 1
1.2 國內(nèi)外研究現(xiàn)狀 1
1.3 主要研究內(nèi)容 2
1.4 研究的目的和意義 2
2 閉式模鍛概述 4
2.1 引言 4
2.2 閉式模鍛工藝的制定 5
2.2.1 鍛件的工藝性分析 5
2.2.2 閉式模鍛工藝過程的制定 5
3 齒輪成形工藝分析及設(shè)計(jì) 6
3.1 冷精鍛 6
3.2 熱精鍛 6
3.3 溫精鍛 6
3.4 工藝方案制定 7
3.4.1工藝性方案 7
3.4.2工藝比較 7
3.5 鍛件圖制定 8
3.6毛坯選擇 9
3.6.1毛坯體積確定 9
3.6.2毛坯形狀選擇 9
4 金屬塑性成形過程的分析方法 11
4.1 概述 11
4.2金屬塑性成形過程的有限元仿真技術(shù) 11
4.2.1金屬塑性成形過程的有限元仿真技術(shù)概述 11
4.2.2金屬塑性成形過程的剛(粘)塑性有限元法概述 12
4.2.3金屬體積成形過程的有限元模擬概述 12
5 關(guān)于坯料尺寸確定的模擬分析 14
5.1 不同坯料尺寸下齒輪的充填效果 14
6 關(guān)于成形溫度確定的模擬分析 16
6.1 40Cr極限損傷因子的計(jì)算 16
6.1.1 40Cr的動(dòng)態(tài)壓縮試驗(yàn) 16
6.1.2 40Cr虛擬鐓粗實(shí)驗(yàn) 16
6.2不同溫度對(duì)40Cr損傷因子的影響 19
6.2.1 冷鍛 19
6.2.2 溫鍛 21
6.3本節(jié)模擬結(jié)果總結(jié) 27
7 模具設(shè)計(jì)及三維造型 29
7.1 概述 26
7.2齒輪鍛件的三維實(shí)體造型 29
7.3凹模型腔造型 31
7.4模具總裝圖 32
7.5工作原理 33
7.6設(shè)備選擇 33
8 結(jié)論 34
9 致謝 35
參考文獻(xiàn) 36