精冲模具在冲压过程中的温升研究

Study of die temperature rising in fine blanking process

为了研究精冲过程中剪切区温升对模具的影响,设计制造了一副能够安装热电偶以测量精冲过程中模具温度变化的精冲模具,并对4种不同材质板料在实时连续冲裁过程中的模具温度变化进行测量实验。采用基于热力耦合的有限元方法对连续精冲过程的温度变化进行模拟研究,模拟结果显示,精冲塑性好的板料模具温升较小;材料强度越高,料厚越厚,模具温升越大;待测点处温度都是前几次冲压过程快速升高,然后达到稳定状态,这与实际测量结果吻合。该有限元方法能有效预测精冲工艺温度场。

To study the influence of temperature rising in sheared region during fine blanking process on the die, a special fine blanking die fixed with thermocouple to measure the temperature change of die was designed and manufactured. Real-time measurements of the tem- perature for the die in the continual fine blanking process with four kinds of sheet metal were carried out. The temperature change in the continual fine blanking process was simulated by using coupled thermal-mechanical finite element method. The results show that the tem- perature rising is smaller when fine blanking the sheet metal with better plasticity. If the tensile strength is higher and the material thick- ness is thicker, the temperature rising will be bigger. The temperature rises rapidly in the previous blanking processes, then reaches an equilibrium state, which is in accordance with the actual experiment. The temperature field with fine blanking process can be effectively predicted by using the finite element method.