Development And Study On Experimental Device Of Pre-stressed Strip Wound Dies

Strip-wound pre-stressed die is to suit the circumstance of manufacture under high temperature and ultra high pressure, especially for cold-forging, cold-extruding and diamond dies. The using of strip-wound pre-stressed die is more predominant comparing with multi-pre-stressed ring dies. The radial stress of multi-pre-stressed ring dies decreases from internal ring to external ring gradually. On the contrary the tangential stress increases from internal ring to external ring .Therefore the outmost ring is caused damage regularly. But the layer of Strip-wound pre-stressed die can be deem an integral ring. Furthermore we can change the stress between the layers of strip according to different mode. It is very important for basic thesis researching of Strip-wound pre-stressed die. It can promote the developing in the domain of material manufacture and dies in our country.Thin steel strip of high-strength is employed to wind around the die insert. The tension in the steel strip can be controlled and accommodated according to the request that makes it impossible to utilize the potential ability of material intensity. The machine which can product Strip-wound pre-stressed die is the research in this thesis under guidance of contemporary design method include computer aided engineering, computer aided design, design for cost and design for assembly, etc. The figure of the variable tension winding device is established by SolidWords software. And the variable tension part and the fixing method of the die cylinder is analyzed by Ansys software to obtain the optimal pre-stress distribution of die core by controlling the steel strip layers'large tension. And the pivotal parts of the special wind apparatus are analyzed by using the finite element method. The experiment of cementation shows us how to solve the fixation problem of the steel strip and the die cylinder.Firstly, two schemes are proposed that include using direct current motor for controlling center and using solenoid proportional valve for controlling center. The two schemes to obtain variable tension both can gain large tension in the steel strip and realize the tension real time controlling.Secondly, the mechanics parameter of the steel is obtained by tensile test for the finite element analysis model that is for analysis process when the steel gets through the apparatus. And the clearance is ascertained through finite element method.Thirdly, in this paper the new fixing manner between the die cylinder and the apparatus. Moreover, the paper put forward the security during the process of the die cylinder stillness, star-up moment and working by using the finite element analysis.Fourthly, a fixing method by glue between the steel and the die cylinder is testified feasible. And the length of the steel strip to overlap the die cylinder is obtained by calculate when we need glue the two material.To sum up, the conclusion of this paper provides reference to design the special winding apparatus. The research also contains great significance in improving guiding the apparatus manufacturing and arts and crafts when we produce strip-wound pre-stressed dies.