Research On Board-Fins Rolling Method And Forming Process Simulation

Board-fins is widely used in the field of heat exchange such as the computer CPU radiator,display card radiator,and other semiconductor components radiator. At present,the manufacturing methods include the extruded, the fold fin, the crimped fin, the skiving and so on. These methods have some problems such as technical complexity, fins falling, high rate of rejection, high cost and so on. In this paper, aiming at the problems existed in present methods,a new rolling technology used to process board-fins was developed based on the traditional rolling principle. The forming process, forming principle and key techniques were studied.Based on the analysis of plasticity roll forming principle and relative motion between rolling tool and workpiece, the structure and dimensions of the rolling tools were designed according to the specifications of the fin shape. The finite element model of rolling tool and the workpiece were established. The forming process was simulated with Deform-3D, the three-dimensional dynamitic simulation of the board-fins rolling process was realized.The strain relation of tracing points on workpiece and the metal flowing rule of forming process were analyzed in every rolling pass of the board-fins roll forming. The generation causes of crack and accumulation were analyzed, and some measures were proposed to improve the cases. The simulation results showed that the measures are effectiveness.By analyzing strain and stress state and deformation velocity field of the workpiece in rolling process, the tool's constraint conditions imposed on the fin space which can well control metal flowing were improved, which provided an guideline to the rolling tool design.Rolling speed, amount pushed down and friction coefficient have important influence on the Board-fins rolling. Taking the three technology parameters as the factors and controlling the load force rang and accumulation volume effectively as the target, the orthogonal table was established and simulation experiments were carried out, the optimal parameters of rolling were obtained.The experiments were carried on the refitted experiment equipment. The experimentalresults were consistent with simulation results. This conclusion verified the validity of the proposed board-fins rolling method and effectiveness of the simulation model.