汽車鋼質同步環(huán)精密成形與提高模具壽命的研究

摘    要

本文針對重型汽車、大客車上使用的鋼質同步器齒環(huán)一次鍛造成形的關鍵和
難點問題進行了深入研究。由于同步器齒環(huán)的齒形是漸開線的，齒部圓角半徑小，在成形過程中容易出現齒形部分充填不飽滿。同時，在成形過程中，模具受力相當復雜；在凹模齒形型腔入模圓角處，當材料從橫向與縱向流入型腔時，激烈的塑性變形引起模具表層溫度迅速上升，在這種情況下模具軟化加劇且磨損嚴重，造成模具使用壽命低。另外，齒形和外表面屬于精密成形，成形之后不再進行機加工，對成形過程的工藝參數控制要求很高。
為解決上述問題，利用計算機數值模擬手段，全面分析了汽車鋼質同步環(huán)鍛造成形工藝，對成形中材料的流動方式、成形過程、缺陷預測、模具結構優(yōu)化進行了研究，分析了不同成形階段材料的流動情況及模具結構與坯料尺寸對鍛件質量的影響，針對模具壽命問題，從模具溫度和應力的角度重點對鋼質同步環(huán)成形過程中凹模的壽命進行了研究。
實驗結果表明：通過對同步齒環(huán)成形過程分析，優(yōu)化工藝及模具結構，提高了模具壽命和材料利用率。

關鍵詞：鋼質同步環(huán)，精密成型，數值模擬，模具壽命，成型工藝

ABSTRACT

This topic is originated from the Sichuan Luzhou Changjiang Machinery Limited Company which project is studying on precisely deforming of the automobile steel synchronous ring and enhancing the die life.
Steel gear of synchronizer is an asymmetric ring thin wall part with several spline
teeth. It is mainly used in gearshift. It is an issue for forging process and mould design because its complex shape which results in insufficient filling, folding and so on. With the development of auto industry, a lot of gears of synchronizer are needed, but it is difficult to get a good satisfactory product in our country.
    The key problems of the copper gear which is used in heavy-duty car and big-bus
during the forging process are discussed in this paper. The teeth are not fully filled usually because of  its small radius due to its involutes profile.Meanwhile the die life is very short because the stress state is quite complex. When the material flows in the cavity along transverse and longitudinal direction, drastic deforming of the billet result that the temperature on the surface raises rapidly, die soften and some parts of the die severe wear. On the other hand,the gear won’t be manufactured any more so it is very important to control the processing parameters.
To overcome these problems, the forming of the gear is analyzed based on numerical simulation,also,studying on the flow of material, forming process, flaw prediction and the optimization of the mould structure. The rules of the material flowing in the cavity in different forming stages and the effects of the size the billet and the mould structure on the quality of the piece are analyzed.Aim at the life time of mould, the life time of the die is studied based on the temparature and stress.
Experiment verification shows through the analysis of the forming of Steel gear of synchronizer,optimization of the technics and mould structure,the life time of die and the using ratio of material are improved.

Key words：Steel gear of synchronizer, Precision forming, Numerical simulation, Mold life, Forming technology
 
 

 
目   錄

摘要 Ⅰ
ABSTRACT Ⅱ
1緒論 1
  1.1 課題來源及意義 1
  1.2國內外同類技術比較 1
1.3現階段存在的主要問題與原因 1
1.4 本課題的研究內容與目標………………………………………………...2
1.5 本課題的主要研究方法………………………………………………......2
2 同步環(huán)精密模鍛工藝設計…………………………………………….4
2.1 零件的工藝性分析………………………………………………………4
2.2 同步環(huán)精密模鍛成形工藝要求…………………………………………….4
2.3 同步環(huán)精密模鍛工藝制定………………………………………………...5
2.3.1 工藝方案比較選擇…………………………………………………..5
2.3.2 鍛件圖制定………………………………………………………...5
2.3.3 坯料制備…………………………………………………………..6
2.3.4 同步環(huán)成形工藝………………………………………….................7
3 同步環(huán)精密成型數值模擬與實驗研究……………………………….8
3.1 數值模擬的基本理論…………………………………………………….8
3.1.1 金屬塑性成型概述…………………………………………………..8
3.1.2 基本假設與基本模型………………………………………………...8
3.1.3 粘塑性基本方程……………………………………………………..9
3.2 模型簡化及模擬條件…………………………………………………….9
3.3 成形過程分析…………………………………………………………..11
3.3.1 無飛邊槽模具結構成形……………………………………………...11
3.3.2 帶阻力墻模具結構成形……………………………………………...14
3.3.3 基本飛邊槽模具結構成型……………………………………………16
3.3.4 小結……………………………………………………………...17
3.4 坯料定位方式優(yōu)化……………………………………………………...19
3.5 實驗條件……………………………………………………………...20
3.5.1 模具預熱………………………………………………………….20
3.5.2 模具冷卻………………………………………………………….20
3.5.3 其他……………………………………………………………...20
4汽車鋼質同步環(huán)模具設計……………………………………………..21
4.1 模具設計概述………………………………………………………21 
4.1.1 模具工作尺寸與鍛件尺寸的關系………………………………………21
4.1.2 模具工作尺寸影響因素………………………………………………22
4.1.3 模腔形狀設計………………………………………………………23
4.1.4 模具凸、凹模及裝配圖………………………………………………25
4.3 模具材料………………………………………………………………26
5模具制造………………………………………………………………..28
5.1模具工作環(huán)境概述……………………………………………………….28
5.2 科學合理選擇模具材料…………………………………………………..28
5.3 模塊科學合理鍛造……………………………………………………....29
5.4 模具強化熱處理………………………………………………………...29
5.4.1 模具強韌化處理…………………………………………………….30
5.4.2 模具表面強化處理…………………………………………………..30
6 同步環(huán)成形問題對策………………………………………………….32
6.1 模具的冷卻……………………………………………………………32
6.2 頂料裝置………………………………………………………………33
6.3 模具的堆焊…………………………………………………………….34
6.4 模具的滲氮處理………………………………………………………...35
7 結論…………………….........................................................................36
參考文獻………………………………………………………………….37
致謝……………………………………………………………………….39