直角形支架工艺设计(共13页)

1、精选优质文档-倾情为你奉上一、造型材料选择··············································

2、83;·································1二、浇注位置及分型面的确定··············&

3、#183;·················································&

4、#183;·1三、铸造工艺参数设计··············································&#

5、183;····························11.加工余量的选择···················

6、3;·················································

7、3;·········22.铸件孔是否铸出的确定······································

8、83;·································2 3.起模斜度的确定··············

9、3;·················································

10、3;··············24.铸造圆角的确定··································

11、·············································3 5. 铸造收缩率的确定···

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13、;······················46.考虑加工余量后的尺寸·························

14、3;··············································4 四、造型方法的设计··

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16、;·····························4五、木模的设计···················

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18、83;·················51.木模的外形设计·······························

19、;·················································62.木模

20、的设计尺寸·················································&

21、#183;······························6六、浇注系统和冒口设计·················&

22、#183;·················································&

23、#183;·········71.浇注系统选择······································

24、3;···········································7.2冒口的选择·····&#

25、183;·················································&#

26、183;·····························7七、铸型装配图设计··················

27、3;·················································

28、3;················8八、设计体会································

29、83;·················································

30、83;········10参考文献········································

31、83;················································11专心-专注-专

32、业一、铸造合金和造型材料的选择 1. 铸造合金的选用因为此次制造的直角形支架使用时负载比较大，要求具有比较高的强度，故采用铸钢ZG270-5002. 造型和造芯材料由于本次课程设计的铸件是中等批量生产，所以造型和造芯的方法应采用灵活多样，适应性强的手工造型。但它有生产率低，劳动强度大，铸件质量不易稳定的缺点。造型方法可选用砂箱造型，其操作方便，无论是大、中、小型铸件，还是大量、成批和单件生产均可采用。型砂选择：铸钢用的型砂和泥心砂，其主要的组成部分是石英砂和耐火粘土。作为造型材料的沙子性质，由砂粒形状和大小，氧化硅的含量，以及沙子中存在的各种混合物来确定。该铸件型砂选用瘦沙（粘土含量210%）

33、来代替石英砂。在湿模造型时，小型和中小型钢铸件泥心砂可以采用小颗粒的半肥沙（粘土含量1020%）作为附加物加入石英砂中。加入的耐火粘土，其工艺试样的抗压强度应为0.50.6kg/mm2。耐火粘土应该是白色或者淡灰色的，不应有可被肉眼看出的混杂物，如砂子、矿石、石灰等。碎粘土所含水分不应超过2%。（铸件材料是铸铁时，制造湿砂型的粘土砂所用粘土为膨润土，湿抗压强度一般为80-120kpa。含水量为4.5-5.5，透气性为60-100，型砂配比70/140目占33，100/200目占17%， 红砂占50%。芯砂选择油砂或水玻璃砂。二、浇注位置及分型面的确定 零件尺寸如下图所示，零件分型面尽可能选择在

34、铸件的最大截面处，并尽量使铸件的大部分或全部置于同一砂箱内，则取零件330x260的面为分型面，采用两箱造型，330x260的平面下部分全部在下箱，330x260平面上部分的4个凸台在上箱。零件的浇注口应该选择在零件的壁厚处，并且尽量减少流动的距离，综合考虑浇筑位置选择在支架两个大平面相交的的中心位置，在另一面设置冒口。三、铸造工艺参数设计 确定铸造工艺参数必须以零件尺寸为依据，零件的详细尺寸如上图所示。1.加工余量的选择该直角形支架为成批、大量生产，采用手工造型，由材料成型工艺基础P54表1.11和表1.12查得尺寸公差等级CT应为1114，选12级，加工余量RMA应选GK,选G。由课程设计

35、题目知基本尺寸330mm，查材料成型工艺基础P56表1.13查得，顶面加工余量取3.5mm，侧面加工余量取2.8mm，加强筋面加工余量取3.5mm，结果如下图所示，2.铸件孔是否铸出的确定因为该铸件材料是ZG45钢，成批生产，孔径17mm，由材料成型工艺基础第三版P69 表4-4查得铸件的最小铸出孔直径是30mm50mm，则该孔不用铸出。结论：该孔径为17mm的孔不用铸出，铸造完成后采用机械加工钻出该孔。3.起模斜度的确定根据标准铸件模样起模斜度中的规定，该铸件选用增加铸件厚度的起模斜度形式如图2.3：图 2.3 起模斜度用手工方法加工模具时用宽度标注，该铸件模具是木模，高度230mm，由材料

36、成型工艺基础第三版 P57表1.14砂型铸造时模样外表面及内表面的起模斜度查得起模斜度2.53.5mm，取3mm。结论：起模斜度为3mm4. 铸造圆角的确定根据铸件的圆角确定铸造圆角，壁的连接和拐角处要做成圆弧过度，如图两大平面内圆角半径为20mm，则铸造圆角设为半径为20mm，外圆角半径取416mm。则外圆角1处取5mm图 2.4 尖角所在位置5. 铸造收缩率的确定该铸件材料为铸钢，由材料成型工艺基础第三版P58知铸钢的有阻碍收缩1.3%1.7%，自由收缩1.6%2.0%，该铸件选1.5%，则制造尺寸放大一个线收缩率。 结论：铸造收缩率1.5%。综上所述考虑到铸件的加工余量、收缩量、拔模斜度、铸造圆角、工艺补正量及芯头间隙后的铸件尺寸如图2.5： 图2.5 最后的铸件尺寸四、造型