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件材料為 Q195A,是碳素結構鋼,具有良好的塑性,市場上容易得到這種材料,價格適中。 由以上分析可知,圖示 工 件具有比較好的沖壓工藝性,適合沖壓生產(chǎn)。 2>( ~ 1) ,滿足沖裁件最小圓角半徑。 查表得無護套凸模的最小沖孔尺寸為 =,已知沖裁件最小沖孔尺寸為 4,所以滿足條件。 方案二:落料 ——沖孔復合模。 分析各方案的優(yōu)缺點 方案一:生產(chǎn)率低,工件的累計誤差大,操作不方便,由于該工件為大批量生產(chǎn),方案二和方案三更具有優(yōu)越性。 洛陽理工學院畢業(yè)設計(論文) 7 第 3 章 主要工藝參數(shù)計算 排樣的設計與計算 排樣的設計 該零件是矩形零件,直排時材料的利用率較高。此沖裁件選用無側壓裝置,無側壓裝置時, 條料的寬度計算: 00 ])(2[ ???? ????? ZaDB (33) 導板間的距離為: )(2 ZaDZBA ??????? (34) 式中 B——條料寬度基本尺寸( mm ); A——導板間距離尺寸( mm ); D——垂直于送料方向沖件的基本尺寸( mm ); a——側面搭邊值( mm ); Z——條料與導板間的最小間隙( mm ); ? ——條料寬度的單向偏差,可查表 31。 沖裁力 P=,K 卸、 K 頂、 K 推 由表 33 查得 K 卸 =,K 頂 =,K 推 =。): 35176。 尺寸 0 ? ,查表 34 得,凸模制造公差 T? =,凹模制造公差A? =。 定位方式的選 擇 本制件是大批量生產(chǎn),采用手工送料方式。 卸料方式的選擇 本模具采用倒裝結構,沖孔廢料和工件留在凹模孔洞中,為簡化模具結構,在下模座中開有通槽,使廢料和工件從孔洞中落下。 L=l+2c (51) B=b+2c (52) 式中 l—沿凹模長度方向刃口型孔的最大距離, mm; b—沿凹模寬度方向刃口型孔的最大距離, mm; c—凹模壁厚 (mm), 凹模厚度 KbH? (53) b—凹模孔的最大寬度 (mm) K—系數(shù),見表 51。凹模的結構簡圖如圖 51 所示: 圖 51 凹模的結構簡圖 沖孔凸模的 設計 選用直通式凸模,采用線切割加工,凸模長度一般是根據(jù)結構上的需要而確定的,采用彈性卸料板,其凸模長度用下列公式計算: L=h1+h2 (55) 式中 L—凸模長度, mm h1—凸模固定板厚度, mm h2—凹模厚度, mm 計算得,凸模長度 L=15+25=40mm。根據(jù)整體模具的設計需要,凸凹模的結構簡圖如圖所示。 固定擋料銷的設計根據(jù)標準件,選用擋料銷如圖 54 圖 54 固定擋料銷的結構 選用直徑 d=Φ10 ? mm, d1=υ6mm, h=3mm, L=13mm,材料為 45鋼的 A 型固定擋料銷。 卸料裝置的設計 橡膠允許承受的符合比彈簧大,且安裝調試方便,成本低,因此選用橡膠作為彈性元件進行卸料。這種模柄用螺釘、銷釘與上模座緊固在一起 ,適用于較大的模具。固定板的凸凹模安裝孔與凸凹模采用過渡配合H7/m H7/n6,壓裝后將凸凹模端面和固定板一起磨平。墊板的外形尺寸可與固定板相同,其厚度一般取 3~ 10mm。墊板的外形尺寸為:160mm125mm10mm。螺釘用于固定模具零件,一般選用內(nèi)六角螺釘;銷釘起定位作用,常用圓柱銷釘。導柱為 248。 滑塊行程 滑塊行程應保證坯料能順利地放入模具和沖壓能順利地從模 具中取出 .這里只是材料的厚度 t=,凸模沖入凹模的最大深度 4mm,導料板的厚度 H=12,即 S1=(+12+4)mm=S=100mm,所以得以校核 . 行程次數(shù) 行程次數(shù)為 45/ ,又是手工送料 ,不能太快 ,因此是得以校核 .滿足使用要求。它與壓力機的配合應該遵守下列關系 : (HmaxHd)5≥ H≥ (Hm inHd)+10 洛陽理工學院畢業(yè)設計(論文) 25 式中 Hmax—— 壓力機的最大閉合高度 ,mm。 模具的閉合高度: H 閉 =h1+h2+h3+h4+h5+h6+h7+h8,代入數(shù)據(jù)計算得 H 閉 =( 40+10+15+25+10+34+25+50) mm=205mm 由壓力機型號知 Hm ax=220mm M=45mm Hd=10mm Hmin=Hm ax–M=22045=175mm(M 為閉合高度調節(jié)量 /m) 由 公式: (HmaxHd)5≥ H≥ (Hm inHd)+10 得 (220–10)5≥205≥(175–10)+10 即 205mm≥205mm≥175mm,所以所選壓力機合適 ,即壓力機得以校核。當條料送到指定位置時,上模在壓力機的作用下下行 ,首先推件塊接觸坯料,上模部分繼續(xù)下行,進行沖裁,導柱,導套對上,下模的運動起到可靠的導向,凹模 7 上需設置相應的讓位孔。在這個過程中通過查閱資料,發(fā)現(xiàn)模具的設計可以根據(jù)不同要求和模具工作環(huán)境,設計與之相符的模具。模具在結構上采用了懸臂式落料沖孔復合模。在設計過程中方老師的淵博知識和嚴謹 的治學態(tài)度以及平和的人生態(tài)度是值得我終生學習的,是我以后工作的楷模。無論是參考資料的互借,還是問題的探討,都對這次設計的順利進行起到至關重要的作用。 45 45 35 35 30 30 30 工作臺尺寸 左右 a mm 250 310 370 450 560 610 700 前后 b mm 160 200 240 300 370 380 460 ?洛陽理工學院畢業(yè)設計(論文) 35 外文資料翻譯 PLAIN CARBON STEEL Any steel making process is capable of producing a product that has % or less carbon. With this small amount of carbon, the properties approach of pure iron with maximum ductility and minimum strength. Maximum ductility is desirable from the standpoint of ease in deformation processing and service use. Minimum strength is desirable for deformation processing. However, higher strengths than that obtainable with this low carbon are desirable from the standpoint of product design. The most practical means of increasing the strength is by the addition or retention of some carbon. However, it should be fully understood that any increase of strength over that pure iron can be obtained only at the expense of some loss of ductility, and the final choice is always a promise of some degree. Because of the difficulty of position contro l or the additional operation of increasing carbon content, the cost of higher carbon, higher strength steel is greater than of low carbon. Plain Carbon Steels Most Used. Because of their low cost, the majority of steels used are plain carbon steels. These consist of iron bined with carbon concentrated in there ranges classed as low carbon,medium carbon, and high carbon. With the exception of manganese used to control sulphur, other elements are present only in small enough quantities to be considered as impurities, though in some cases they may have minor effect on properties of the material. Low Carbon. Steel with approximately 6 to 25 points of carbon (%~ %)are rated as low carbon steels and are rarely hardened by heat treatment because the low carbon content permits so little formation of hard magnesite that the process is relatively ineffective. Enormous tonnages of these low carbon steels are processed in such structural shapes as sheet, 洛陽理工學院畢業(yè)設計(論文) 36 strip,rod,plate,pipe,and wire. A large portion of the material is cold worked in its final processing to improve its hardness, strength, and surface finish grades containing 20 points or less of carbon are susceptible to considerable plastic flow and are frequently used as deepdrawn products or may be used as a ductile core for casehardened material. The low lain carbon steels are reality brazed, welded, and fed. Medium Carbon. The medium carbon steels (%~ %)contain sufficient carbon that they may be heat treated for desirable strength, hardness, machinability, or other properties. The hardness of plain carbon steels in this range cannot be increased sufficiently for the material to serve satisfactorily as cutting tools,but the loadcarrying capacity of the steels can be raised considerably, while still retaining sufficient ductility for good toughness. The majority of the steel is furnished in the hotrolled condition and is often machined for final finishing. It can be welded,but is more difficult to join by this method than the low carbon steel because of structural changes caused by welding heat in localized areas. High Carbon. High carbon steel contains from 50 to 160 points of carbon (%~ %). Th