久久久久99精品三人片毛片_黑人无码在线视频_国产一区二区三区免费乱码_国产免费观看精品_中文字幕视频在线一区国产

CNC technology originated from the needs of the aviation industry. In the late 1940s, an American helicopter company proposed it.
The initial idea of CNC machine tool was developed by MIT in 1952. In the mid-1950s, this type of CNC milling machine was used to process aircraft parts. In the 1960s, CNC systems and programming became more mature and improved. CNC machine tools have been used in various industrial sectors, but the aerospace industry has always been a major user of CNC machine tools. Some large aviation factories are equipped with hundreds of CNC machine tools, including cutting machine tools. The parts of CNC machining include the overall wall plate, girder, skin, partition, Propeller of the aircraft and rocket, as well as the casing, shaft, disc, mold cavity of the blade, and the special cavity of the combustion chamber of the liquid rocket engine. The initial development of CNC machine tools is based on continuous trajectory of CNC machine tools, continuous trajectory control. Continuous trajectory control, also known as contour control, requires the tool to move relative to the prescribed trajectory of the part. Later, it vigorously developed point-controlled CNC machine tools. Point control refers to the tool moving from one point to another, as long as it can eventually reach the target accurately regardless of the moving route.