标准件主要标准(外国英语资料).docVIP

标准件主要标准(国外英文资料) In the use of threaded fasteners, more widely used is the bolt nut connection form, and the more application is the pre tightening connection mode, the pre tightening force The utility model can improve the reliability of the bolt connection, the looseness resistance and the fatigue strength of the bolt, and can enhance the tightness and the rigidity of the threaded joint. Threaded fasteners When the connection is in use, there is no pretension or pretension, and the connection is not real. It is generally referred to as under twist, but excessive pretension or unavoidable Excessive twisting can also cause failure of threaded connections. It is well known that the reliability of threaded connections is designed and judged by pretension, but can be measured except in the laboratory Besides, it is difficult to measure intuitively at the assembly site. The tightening force of threaded fasteners is achieved by means of torque or corner. Therefore, when the design is true When the preload is set, what control method should be adopted for the installation? How to specify the tightening torque index? It becomes a key issue, which raises the need for threaded fasteners The study of the relation between torsion (moment) and tension (force) of a piece. The relationship between twist and tension of threaded fasteners involves not only torque coefficient, friction coefficient (including thread friction coefficient and friction coefficient of support surface), yield, fastening, axial force, and yield The test and calculation method for fastening characteristics of a series of threaded joint pairs such as fastening torque and limit, fastening axial force, etc., and also relating to the stress sectional area and the bearing of threaded fasteners The basic terms, symbols, etc of the calculation method of the carrying area. It is also necessary to give the basic rules, major relationships and typical features of fastening of threaded fasteners Tightening method. At p