豆传媒剧在线mv在线观看|传媒剧在线mv入口|9传媒剧在线mv在线看|豆传媒剧mv入口在线看|豆传媒剧在线观看免费|爱豆传媒剧情在线观看Fixture is a large class of tools for carpentry, ironworker, fitter, machinery, electric control and other handicrafts. It is mainly used as a tool to assist in controlling position or action (or both). Many metallurgical tools are produced because of commercial needs, because many types of tools are customized, some to improve productivity, repeat specific actions, or make the work more accurate. Because the design of fixtures is basically based on logic, similar fixtures may be produced separately because they are used in different times and places. After entering the automation and CNC system machines, more and more fixtures are designed to be able to control automatically, and their scientific and technological content is higher and higher. Designers are required to have not only mechanical knowledge, but also electrical control knowledge.