Rapid prototyping technology changed the traditional pattern of product design, which could offer product sample for the designer, reduced design cycle and quicken the schedule of new product design, and it gave the decision - makers visual feeling. ; rp technology provided kinds of molds including resin - boncled mold laminate mold, investment mold and lost foam casting mold and so on for sand casting investment casting and cavityless casting, it could also use direct shell production casting to make pattern dies metal dies die - casting dies injection dies directly, and it could even produce casting products in small scales. the applications of fdm technology in plaster precision casting and the rapid casting technology based on sls technology were introduced, the organic combination between rapid prototyping tecnnology and foundry process, which initiated a new period of rapid manufacturing metal parts, by using advanced new technology alternated traditional foundry industry to make it looked brand - new, thus, the competition of foundry industry would be improved ; rapid prototyping technology offered a rapid economical feasible technical method, common processes of using rapid prototyping technology to produce dies were discussed, in the paper it explored that. the problem of combining rapid prototyping technology with electric arc metal - spraying technology to make metal dies and technics in dies manufacturing of combining rapid prototyping technology with precision casting, rapid tooling based on rapid prototyping, integrated advanced new technology and tradition technology of rapid prototyping manufacture, each superiority were exerted, rapid prototyping technology had been an efficiency measure to rapid update products and develop new product, and to middle -
快速成型技術改變了傳統的產品開發模式,可以為設計者提供產品樣件,縮短設計周期,加快新產品的開發進度,為決策者提供直觀性;快速成型技術迅速提供砂型鑄造、熔模鑄造、實型鑄造用的各種模樣,包括樹脂模、層壓模、熔模和消失模等,還可採用直接制殼鑄造法直接製造熔模鑄造用的壓型、金屬型、壓鑄型、注塑模,甚至直接製造小批量鑄件,介紹了熔積成型技術在石膏型精密鑄造上的應用和基於選擇性激光燒結技術的快速鑄造技術,快速成型技術與鑄造工藝的有機結合,開創了快速製造金屬零件的新階段,對用高新技術改造傳統的鑄造工業,使其面貌煥然一新,增強鑄造行業的競爭能力;快速成型技術為母模的製造提供了一條快速、經濟、可行的技術途徑,討論了利用快速成型技術製造模具的一般工藝方法,探討了將快速成型技術與金屬電
弧噴鍍技術結合起來快速製造金屬模具問題,以及快速成型技術與精密鑄造技術相結合的模具製造工藝,基於快速成型製造的快速模具技術,
集成了快速成型製造高新技術和傳統技術,發揮各自優勢,已成為產品快速更新換代和新產品開發及中、小批量生產的有效手段之一。
Test results indicated : with the hoist of altitude, the increase of ice amount and the rise of pollutant, the average flashover voltage reduced. the character exponent generally depends on the insulator profile, ice amount, ice state and pollution severity etc. by means of a high - speed camera, a data acquisition system and high voltage test facilities, a series of the flashover processes on ice surfaces were record. the experimental results form this study and the subsequent theoretical analyses suggested : the thermal ionization of the air in front of an arc root resulted in arc movement ; the electrostatic force had an auxiliary effect of impelling arc propagation ; the electrical
通過對攝像機、數據採
集系統及高壓試驗裝置記錄覆冰絕緣子表面閃絡電
弧的發展過程的試驗結果進行理論分析得出:
弧根周圍空氣的熱電離導致了電
弧的發展,靜電場力對電
弧的發展起到了加速作用,電擊穿僅發生在閃絡最終的跳躍階段;通過測量閃絡過程中的放電電壓、泄漏電流、閃絡時間、覆冰水電導率、電
弧長度及電
弧半徑等參數,得到了不同階段電
弧(電
弧起
弧階段、電
弧發展階段及完全閃絡)的發展速度、臨界電
弧長度均隨覆冰水電導率的增加而減小。
Cracking failure of centrifugal compressor ' s impellers was analyzed, the welding craters in the impellers led to stress concentration. the unsteady gas flow accelerated the development of cracks in the impeller
摘要針對某石化公司離心壓縮機葉輪多次發生開裂、掉塊等故障以及裂紋形成機理進行了分析。分析結果表明了葉輪開裂原因系疲勞開裂,葉輪焊接缺陷產生了焊接
弧坑,造成表面應力
集中,氣流激振加速了裂紋擴展。
Lying is a sin against the eighth commandment
弧晾?
集?材8兵癸
Sichuan petroleum administration ziyang steel pipe plant ( zspp ) is the designated factory by cnpc to manufacture spiral arc - welded steel pipe ( shortened as " spiral welded pipe " )
四川石油管理局資陽鋼管廠是中國石油天然氣
集團公司螺旋縫雙面埋
弧焊鋼管(以下簡稱螺旋焊管)定點生產廠。
The numerical results show that the double arc transition form can make different cylinder shells eliminate stress concentration at two ends and amend stress distribution of changeover portion
計算結果表明:雙圓
弧式的過渡形式能使不同直徑圓柱殼兩端連接處消除應力
集中和改善過渡段應力分佈。
Stiff arc, with heat concentrated, easy to fill welding wire, so especially suitable for wire filling welding in bicycle area
電
弧挺度好,熱量
集中,填絲容易,特別適宜自行車等行業的填絲焊接。
In this article, we use idea of turning dispersion into convergence and put all the well ' s points into the same unit net to think about it. and answer three questions of the distribution of well drilling by the way of searching for groups of points. fincite - step - searching underthe condition of translationg fcoordinate system or revolving coordinate system. to first question. we find two algo - rithms and make use of data that is given to find the solution. we seek coorlinate of net point is co. 361, 0. 461 ) and mostly four old well ' s points are utilized at the same time by first algorithim, which are no. 2, no, 4, no. 5, no. 10. by second algorithm, we rechon the coordinate of net point is co. 390, 0. 505 ). and that mostly four old well ' s points are utilizld which are no. 2, no. 4, no. 10. to second question, we turn it into the first question by angling awt the center of net point. we seek that mostly six old well ' s points are utilized at the same time, which are no. 1, no. 6, no. 7, no. 8, no. 9, no. 11, when net is angled 0. 78 radian. and net point is translated to ( 0. 75, 0. 076 ) ( at nwe coordinate system ). to third question, wefind a necessary and sufficient condition and affer algorithms, at last, we analyse algorithms
運用化分散為
集中的思想,把所有的井點都放在同一個單位網格內考慮.在坐標可平移、旋轉的條件下,利用尋找點群、有限步驟搜索法,對鉆井布局的三個問題進行了解答.對問題一,給出了兩個不同演算法.並對題目提供的數據進行了求解,演算法1得到的結點為( 0 . 361 , 0 . 461 ) ,最多有4個舊井點被同時利用,它們是第2 、 4 、 5 、 10個井點;演算法2得到的結點為( 0 . 390 , 0 . 505 ) ,最多有4個井點被利用,它們是第2 、 4 、 5 、 10個井點.對問題二,以結點為中心旋轉一定的角度后,歸結為問題一進行求解,求解結果為當網格傾斜角為0 . 78
弧度(相對原坐標系) ,結點平移到( 0 . 75 , 0 . 076 )點(在新坐標系下) ,可被同時利用的最多舊井點為6個,它們是第1 、 6 、 7 、 8 、 9 、 11個井點,對問題三,我們給出了充要條件,並給出了演算法.最後還分析了演算法的優劣性
A simple undirect graph x is said to vertex - transitive, edge - transitive, and arc - transitive, if its automorphism group acts transitively on the vertices, edges and arcs, respectively
如果一個簡單的無向圖的自同構群分別傳遞的作用在它的點
集,邊
集和
弧集上,那麼分別稱這個圖是點傳遞的,邊傳遞的和
弧傳遞的。
Welding in different angles can be conducted owing to highly concentrated arc
由於電弧集中性強,可進行各種姿勢的焊接。