1、一、造型材料選擇················································

2、3;·······························1二、澆注位置及分型面的確定················&#

3、183;·················································1三

4、、鑄造工藝參數設計················································

5、83;··························11.加工余量的選擇······················

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

7、;·······22.鑄件孔是否鑄出的確定········································

8、3;·······························2 3.起模斜度的確定·················

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

10、;············24.鑄造圓角的確定····································&

11、#183;··········································3 5. 鑄造收縮率的確定·····

12、··················································

13、····················46.考慮加工余量后的尺寸····························

14、;············································4 四、造型方法的設計····

15、··················································

16、···························4五、木模的設計·····················

17、3;·················································

18、3;···············51.木模的外形設計·································

19、···············································62.木模的設計尺寸·&#

20、183;·················································&#

21、183;····························6六、澆注系統和冒口設計···················&#

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

23、183;·······71.澆注系統選擇·········································

24、;·········································7.2冒口的選擇·······

25、83;·················································

26、83;···························7七、鑄型裝配圖設計·····················

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

28、;··············8八、設計體會··································

29、3;·················································

30、3;······10參考文獻··········································

31、3;··············································1110一、鑄造合金和造型材料的選擇 1.

32、鑄造合金的選用因為此次制造的直角形支架使用時負載比較大，要求具有比較高的強度，故采用鑄鋼ZG270-5002. 造型和造芯材料由于本次課程設計的鑄件是中等批量生產，所以造型和造芯的方法應采用靈活多樣，適應性強的手工造型。但它有生產率低，勞動強度大，鑄件質量不易穩定的缺點。造型方法可選用砂箱造型，其操作方便，無論是大、中、小型鑄件，還是大量、成批和單件生產均可采用。型砂選擇：鑄鋼用的型砂和泥心砂，其主要的組成部分是石英砂和耐火粘土。作為造型材料的沙子性質，由砂粒形狀和大小，氧化硅的含量，以及沙子中存在的各種混合物來確定。該鑄件型砂選用瘦沙（粘土含量210%）來代替石英砂。在濕模造型時，小型和中小

33、型鋼鑄件泥心砂可以采用小顆粒的半肥沙（粘土含量1020%）作為附加物加入石英砂中。加入的耐火粘土，其工藝試樣的抗壓強度應為0.50.6kg/mm2。耐火粘土應該是白色或者淡灰色的，不應有可被肉眼看出的混雜物，如砂子、礦石、石灰等。碎粘土所含水分不應超過2%。（鑄件材料是鑄鐵時，制造濕砂型的粘土砂所用粘土為膨潤土，濕抗壓強度一般為80-120kpa。含水量為4.5-5.5，透氣性為60-100，型砂配比70/140目占33，100/200目占17%， 紅砂占50%。芯砂選擇油砂或水玻璃砂。二、澆注位置及分型面的確定 零件尺寸如下圖所示，零件分型面盡可能選擇在鑄件的最大截面處，并盡量使鑄件的大部分

34、或全部置于同一砂箱內，則取零件330x260的面為分型面，采用兩箱造型，330x260的平面下部分全部在下箱，330x260平面上部分的4個凸臺在上箱。零件的澆注口應該選擇在零件的壁厚處，并且盡量減少流動的距離，綜合考慮澆筑位置選擇在支架兩個大平面相交的的中心位置，在另一面設置冒口。三、鑄造工藝參數設計 確定鑄造工藝參數必須以零件尺寸為依據，零件的詳細尺寸如上圖所示。1.加工余量的選擇該直角形支架為成批、大量生產，采用手工造型，由材料成型工藝基礎P54表1.11和表1.12查得尺寸公差等級CT應為1114，選12級，加工余量RMA應選GK,選G。由課程設計題目知基本尺寸330mm，查材料成型工

35、藝基礎P56表1.13查得，頂面加工余量取3.5mm，側面加工余量取2.8mm，加強筋面加工余量取3.5mm，結果如下圖所示，2.鑄件孔是否鑄出的確定因為該鑄件材料是ZG45鋼，成批生產，孔徑17mm，由材料成型工藝基礎第三版P69 表4-4查得鑄件的最小鑄出孔直徑是30mm50mm，則該孔不用鑄出。結論：該孔徑為17mm的孔不用鑄出，鑄造完成后采用機械加工鉆出該孔。3.起模斜度的確定根據標準鑄件模樣起模斜度中的規定，該鑄件選用增加鑄件厚度的起模斜度形式如圖2.3：圖 2.3 起模斜度用手工方法加工模具時用寬度標注，該鑄件模具是木模，高度230mm，由材料成型工藝基礎第三版 P57表1.14砂

36、型鑄造時模樣外表面及內表面的起模斜度查得起模斜度2.53.5mm，取3mm。結論：起模斜度為3mm4. 鑄造圓角的確定根據鑄件的圓角確定鑄造圓角，壁的連接和拐角處要做成圓弧過度，如圖兩大平面內圓角半徑為20mm，則鑄造圓角設為半徑為20mm，外圓角半徑取416mm。則外圓角1處取5mm圖 2.4 尖角所在位置5. 鑄造收縮率的確定該鑄件材料為鑄鋼，由材料成型工藝基礎第三版P58知鑄鋼的有阻礙收縮1.3%1.7%，自由收縮1.6%2.0%，該鑄件選1.5%，則制造尺寸放大一個線收縮率。 結論：鑄造收縮率1.5%。綜上所述考慮到鑄件的加工余量、收縮量、拔模斜度、鑄造圓角、工藝補正量及芯頭間隙后的鑄件尺寸如圖2.5： 圖2.5 最后的鑄件尺寸四、造型方