Control arm forging
Control arm forging
Control arm forging
Control arm forging
Control arm forging
Control arm forging
Control arm forging
Control arm forging
As the guiding and force transmitting component of the car suspension system, the control arm transmits various forces acting on the wheel to the vehicle body, and at the same time ensures that the wheel moves according to a certain trajectory, so the control arm should have sufficient rigidity, strength and service life. In the actual open die forging production process, there are two main problems: First, the parts are prone to cracks, resulting in scrapped parts, and second, the utilization rate of materials is too low, less than 50%. Therefore, it is necessary to study a forming process that can simultaneously produce large quantities and reduce production costs, improve forming quality, material utilization rate, and production efficiency.
Through numerical analysis of the control arm bending and open die forging process, the metal flow in the forming process was analyzed, and the final forging die was optimized. The scheme of the forging die with the resistance wall was proposed and the forming process was carried out. Analysis.
1. Forming Process Design of Automobile Control Arm Forgings
Through the analysis of the structure of the control arm, the production process is as follows: blanking-heating-rolling forging-bending-die forging-control arm forging quality inspection. According to different deformation conditions, the bending is divided into free bending type and clamping bending type: the curved cavity is designed according to the bending characteristics of the aluminum alloy forging; the appropriate blank is selected according to the calculated blank sectional drawing, and the bending and final forging process is performed. Corresponding numerical simulations were carried out to analyze the final forging process.
2. Finite element model
In the forming process of the control arm forging, the elastic deformation part is much smaller than the plastic deformation part, so the elastic deformation can be neglected to establish the rigid plastic material model. The mold material is defined as a rigid body, the workpiece material is selected ALUMINUM-6061, the friction between the blank and the mold The method is shear friction, and the friction factor is defined as 0.4. Due to the large size, complex shape and long simulation period of the aluminum alloy control arm, in order to save the simulation time, the blank is divided by 40,000 tetrahedral meshes.
3. Simulation analysis results of ordinary final forging die
According to the three-dimensional model of the forging, a simple three-dimensional model of the final forging cavity is established. According to the characteristics of the part itself and the characteristic of the middle curved part in the cylindrical shape, the vertical corner of the branch bud and the arm is set as the bridge of the flash groove. The part is used to increase the resistance of the metal to the chamber, increase the friction force to promote the flow of the metal to the cylindrical shoot buds, and trimming it after forming.
From the velocity field distribution, when the material utilization rate is 50%, the final forging die of the conventional flash tank is used for the final forging forming, and the cylindrical branch bud portion is not filled and the folding phenomenon occurs. At the end of the forming of the control arm forging, the billet of the cylindrical branch buds flows in a chaotic manner, and there is a phenomenon of the intersection of the speed directions, which is prone to defects. In summary, the material filling ability is poor when using the conventional burr groove, and the final forging die cavity needs to be improved.
4. Simulation analysis results using a resistance wall
It can be seen from the previous simulation results that if the diameter of each part of the blank is reduced and the material utilization rate is increased to 70%, cylindrical buds are more difficult to fill if a conventional burr groove is used. In order to improve the filling performance of the material and improve the utilization of the material, the resistance wall is designed in the difficult part of the mold cavity.
When the middle part of the cavity has been substantially filled, the metal is in a state of three-way compressive stress, and at this time part of the metal flows to the bridge of the resistance wall because the frictional resistance of the bridge is 2br. Value, equal to t). The larger the bridge width b is, the greater the frictional resistance is, which exacerbates the shear stress between the flowing metal and the stationary metal. The tensile stress at this time is relatively large. As the mold continues to descend, the cavity is continuously filled, the free surface is continuously reduced, the maximum compressive stress value is continuously increased, and the maximum tensile stress value is continuously decreasing. When the bridge filling is satisfied, due to the obstruction of the resistance wall, the bridge metal is in the three-way compressive stress, and the unfilled portion of the cavity is smaller than the resistance wall bridge due to the existence of the free surface.
It can be known from the equivalent strain that the equivalent strain value of the control arm forging body is relatively uniform, and a relatively uniform microstructure performance can be obtained.
5. Conclusion
(1) Through the analysis of the control arm forging structure, the production process of the forming process is rationally designed.
(2) The final forging die of the conventional forging die is simulated, and the defects appearing are analyzed and the folding zone is easily formed.
(3) The final forging die was optimized. A resistance wall was designed to increase the material utilization rate to 70% and obtain qualified forgings.