摘 要

汽車發(fā)動機曲軸，是汽車工業(yè)中一種典型的復(fù)雜模鍛件，其成形難度大，對成形工藝要求高。近年來，由于汽車的重載、高速和高可靠性的要求，對曲軸的
性能要求也越來越高，因此如何改進曲軸的加工工藝以盡可能地提高曲軸的機械
性能和壽命就顯得尤為重要。
曲軸類鍛件鍛造工藝復(fù)雜，其可行性、穩(wěn)定性、成形質(zhì)量（含充滿與否、折
疊、組織缺陷）、材料利用率以及如何降低載荷提高模具使用壽命等，都是在制
訂曲軸成形工藝過程中必須重點考慮的。
本文對曲軸的精密模鍛成形工藝和國內(nèi)外研究現(xiàn)狀作了簡要介紹，選擇平面
四拐曲軸作為典型件，詳細介紹了曲軸模鍛工藝的分析和設(shè)計，運用三維造型軟件在CAD平臺下進行曲軸的模鍛工藝與模具設(shè)計中相關(guān)問題的 CAD實體三維造型。根據(jù)剛塑性有限元基本原理，利用數(shù)值模擬軟件對曲軸的成形過程進行數(shù)值模擬，分析了飛邊槽、阻力墻參數(shù)對曲軸精密模鍛成形過程中的金屬流動情況、模具型腔充填情況以及材料利用率的影響。由模擬結(jié)果，分析造成鍛件缺陷的因素并通過各種方案的模擬結(jié)果,對比選出能夠鍛出合格鍛件的工藝及模具參數(shù)。


關(guān)鍵詞：曲軸，模鍛，模具設(shè)計，工藝分析，數(shù)值模擬,工藝優(yōu)化











ABSTRACT

The crankshaft of automobile is one typical die forging part with complex structure,which is usually formed by a complicated process under the high forming requirement.In recent years, due to the demand of high performance of automobile, such as heavy load, high speed, high reliability, etc., the requirement of crankshaft’s performance has also been uprated greatly. Therefore, it is of great importance to optimize the forging process to improve the mechanical performance of crankshaft.
The forging process of crankshaft is very complicated, the feasibility, stability,
quality of forming (including fulfilling, wrinkle and structure defect), material yield and mould lifetime, etc. are all the key factors that should be considered with emphasis during the forging process decision
This paper briefly introduces the precision die forging process of crankshaft and the research status of the forging development home and abroad, choosing the plane four turner crankshaft as a typical forging part, as the typical forge piece, particularly introduced the author’s work on analysis and designs of production processes, By the use of the CAD system , the three-dimensional model of crankshaft and die can be set up parametrically.According the rigid-plastic finite element method, using the finite element numerical simulation soft,the influence on the metal flow, mould filling,and die load, and material yield from the parameters of web and resistance wall are analyzed. Using simulate results, find and analyzes the factors caused the defects of forging, And by the simulate results,elected the production processes and die parameters to product qualified crankshaft forge piece.


Keywords：crankshaft ,die forging，die design，technology analysis, numerical simulation, technology optimize


目 錄

中文摘要 I
ABSTRACT II
1緒論 1
1.1引言 1
1.2 曲軸的自由鍛工藝 2
1.3曲軸的模鍛工藝 2
1.4國內(nèi)外曲軸鍛造研究現(xiàn)狀 2
1.5本課題的主要研究內(nèi)容 3
2曲軸模鍛成形工藝設(shè)計 5
2.1精密模鍛工藝概述 5
2.2曲軸的模鍛工藝概述 5
2.2.1曲軸的分類 5
2.2.2曲軸鍛造工藝分類 6
2.2.3模鍛法加工曲軸 7
2.3曲軸精鍛工藝分析 7
2.4鍛件的材料特性 9
2.5鍛造設(shè)備類型的選擇 10
2.6設(shè)備噸位的選擇 10
2.7熱鍛件圖的設(shè)計 12
2.8制坯工步的確定 14
2.8.1制坯工步的作用 14
2.8.2初擬計算毛坯 15
2.9坯料尺寸的確定 17
2.10制定工藝卡片 17
3曲軸模具設(shè)計 18
3.1模具設(shè)計的CAD/CAM技術(shù) 18
3.2熱模鍛壓力機模具設(shè)計要領(lǐng) 18
3.3模塊的設(shè)計 19
3.3.1模塊的形式與尺寸 19
3.3.2飛邊槽的形式和尺寸 19
3.3.3模膛的設(shè)計 20
3.3.4排氣孔的設(shè)計 21
3.3.5模架的設(shè)計 22
4曲軸成形過程的數(shù)值模擬和分析 25
4.1數(shù)值模擬的意義 25
4.2剛粘塑性有限元法簡介 25
4.3鍛造過程模擬 26
4.3.1滾擠制坯的模擬 26
4.3.2采用常規(guī)飛邊槽模具結(jié)構(gòu)終鍛的模擬 27
4.4模擬結(jié)果分析 28
4.5造成鍛造缺陷的影響因素分析 29
4.6方案的優(yōu)化和改進 30
4.6.1模具結(jié)構(gòu)的優(yōu)化 30
4.6.2制坯模膛的優(yōu)化 35
4.6.3坯料尺寸的優(yōu)化選擇 38
4.6.4方案確定 39
5結(jié)論 40
參考文獻 42
致 謝 44