发动机箱体铸造工艺设计

封面

摘要

本文综合分析了采用铸造工艺生产汽车发动机箱体的方法，从铸造设备、铸造模具设计、生产工艺、铸造生产中常见的问题及对策等多个角度，对铸造工艺的技术动向以及今后的研究课题提出了自己的见解。

对国内外发动机箱体铸造生产进行了总结,其材质主要以C(质量分数,下同):3.15%~3.3%,CE:3.95%~4.05%,Si/C:0.6%~0.7%的灰铸铁为主。一般选择冲天炉-有芯工频电炉进行熔炼,孕育剂仍普遍采用75SiFe,立浇底注式浇注系统和保温冒口有利于获得优质箱体,冷芯制芯工艺已逐渐取代热芯工艺。通过提高浇注温度、型砂紧实率等措施可减少箱体常见缺陷渗漏的出现。

铸造过程中合金配比工艺研究当箱体中含Cr量从0．308％上升到0．343％并不能明显增加珠光体数量和片间距的等级，但是可使铸件各部位的硬度总体呈上升趋势。铸件抗拉强度值上升幅度很大。一般可上升20～30MPa．在箱体中加入Sn可以明显提高铸件的布氏硬度和组织中的珠光体含量，但对于提高珠光体的片间距等级和减少渗碳体量则效果不明显。

关键词：铸造工艺；灰铸铁；模具设计

ABSTRACT

This paper analyzes the use of the casting process to produce automobile engine box approach from many angles common foundry equipment, casting mold design, manufacturing process, casting production problems and countermeasures on the casting process technology trends and future research put forward their own views.

For domestic and engine block, cylinder head casting a summary, the material mainly C (mass fraction): 3.15% ~ 3.3%, CE: 3.95% ~ 4.05%, Si / C: 0.6% ~ 0.7 % of gray cast iron main. Generally choose cupola - a core-frequency electric furnace smelting, inoculant is still widely used 75SiFe, Li pouring bottom gating and riser system is conducive to quality block, cylinder heads, cold-core making process has been gradually replaced by heat core processes. By increasing the pouring temperature, sand compaction rate and other measures to reduce the block, cylinder heads common defect leakage occurs.

Alloy Casting process, when the ratio of the cylinder Cr content increased from 0.308% to 0.343% did not significantly increase the number and spacing of pearlite grade, but can cast various parts of hardness overall upward trend. Casting a great tensile strength values rise. Generally rise 20 ~ 30MPa. Adding Sn in the cylinder can significantly improve the casting Brinell hardness of pearlite content and organization, but for improving the pearlite spacing levels and reduce the amount of cementite is ineffective.

Keywords: casting; gray iron; mold design

摘要 (2)

ABSTRACT (3)

1 前言 (6)

1．1课题背景 (6)

1．2箱体铸件国内外研究现状和发展趋势 (6)

1．2．1国外发动机箱体铸造技术生产状况 (7)

1．2．2我国发动机箱体铸件的生产状况 (7)

1．3灰铸铁箱体材料的发展 (8)

1．3．1箱体材料要求 (8)

1．3．2灰铸铁箱体材料 (8)

1．3．3灰铸铁的组织和几种合金元素的影响 (9)

1．3．4国内外箱体生产中灰铸铁材质的选择 (13)

1．4本课题研究的内容 (18)

2 低合金灰铸铁箱体工艺简介 (19)

2．1生产设备及原材料 (19)

2．1．1生产设备 (19)

2．2结构简介 (19)

2．3材质要求 (20)

2．4造型及浇注系统设计 (21)

2．4．1造型工艺 (21)

2．4．2浇注系统 (22)

2．5制芯及组芯工艺方案设计 (23)

2．5．1制芯 (23)

2．5．2组芯 (23)

2．6孕育剂的加八方法 (25)

2．6．1孕育机理及目的 (25)

2．6．2生产孕育铸铁铸件的条件 (25)

2．7．1原材料 (26)

3 合金元素对发动机箱体性能的影响 (27)

3．1引言 (27)

3．2试验装置及试验方法 (28)

3．2．1试验装置 (28)

3．2．2原材料 (28)

3．2．3制样 (28)

3．3铬对箱体力学性能和金相组织的影响 (29)