[作者：aowl] [日期：18-07-31] [瀏覽次數：] [來源：http://www.mobiinet.com]
一、閥門毛坯的製造工藝及檢驗工藝比較複雜 First, the manufacturing process and inspection process of valve blank are rather complicated.閥門的鑄件毛坯是結構叫複雜的薄壁殼體件。其鑄件要求表麵光潔、鑄字清晰，特別是要有致密的缺陷。為了滿足上述要求，鑄造時應采取一係列工藝措施，如選用高耐火度的造型材料並控製型砂水份、造型時應分層打實以保證砂型硬度，采用合理的澆帽口係統及嚴格控製澆注速度和溫度等。由於技術要求較高，閥門毛坯的鑄造工藝遠較一般鑄件複雜。 The casting blank of valve is a complex thin-walled shell part. The casting requires smooth surface and clear casting, especially with dense defects. In order to meet the requirements mentioned above, a series of technological measures should be taken in casting, such as selecting high refractory molding materials and controlling the moisture of the molding sand. The molding should be layered to ensure the hardness of the sand mold. The proper casting mouth system and strict control of the pouring speed and temperature are adopted. Because of the high technical requirements, the casting process of valve blank is far more complicated than ordinary casting.此外，閥門毛坯除檢查尺寸，位置精度及外觀外，有的還有作金相組織、力學性能、耐腐蝕性能及無損探傷等多種檢驗，故閥門的檢驗工藝也較複雜。 Besides, in addition to checking the size, position accuracy and appearance of the valve, there are many kinds of inspection such as metallographic organization, mechanical properties, corrosion resistance and nondestructive testing, so the inspection technology of the valve is also complicated.二、機械加工難度大 Two. Mechanical processing is difficult由於閥門材料的各類繁多，除各種鑄鐵、碳素鋼外，其大部分高強、耐腐蝕和高硬材料的切削性能都很差，很難使零件達到規定的加工精度和表麵粗糙度。而閥門密封麵的幾何型狀精度和表麵粗糙度的要求很高，因此更增加了閥門機械加工難度。 Because of various kinds of valve materials, the cutting performance of most high strength, corrosion resistant and hard materials is very poor except for various kinds of cast iron and carbon steel. It is difficult to make the parts reach the required machining precision and surface roughness. However, the requirement of geometric shape precision and surface roughness of valve sealing surface is very high, so the machining of valve is more difficult.同時，閥門材料的切削性能差，又給閥門的加工方法、刀具材料、切削用量、工藝裝備等方麵帶來了很多新的問題。 At the same time, the cutting performance of the valve material is poor, and it also brings a lot of new problems to the processing method, cutting tool material, cutting amount and technical equipment of the valve.三、閥門零件在機床上安裝比較困難 Three. It is difficult to install the valve parts on the machine tool閥門主要零件的結構、形狀比較複雜，有些零件屬壁薄、細長件，剛性差。在機床上加工時，定位和裝夾都比較困難，因此往往需要複雜的專用夾具。 The structure and shape of the main parts of valves are rather complicated. Some of them are thin, slender and rigid. When machine tools are processed, positioning and clamping are difficult, so complex special fixtures are often needed.