Problems In The Design Of Die-Casting Molds

- Sep 04, 2018-

2. Reasonable structure


The structure is advanced and reasonable, the operation is convenient, and the high die-casting efficiency has the characteristics of fast filling, quick mold opening, flexible and reliable demoulding mechanism and high degree of automation.


(1) Arrangement of gating system and drainage system


In the process of filling and pressing the mold cavity, the pouring system and the drainage system are an inseparable whole, which together play a controlling role in the filling process and are an important factor in determining the quality of the die casting.


The overall layout of the gating system and the drainage system shall be based on the structural characteristics of the die casting, the geometry, the exhaust conditions of the cavity, etc., and in combination with the form of the die casting machine selected, for the sprue, sprue and inner The location, form, size, direction of the diversion, and the setting of the drainage system are considered comprehensively and initially determined. In particular, the position and form of the ingate are important factors in determining the filling effect of the molten metal and the quality of the die casting.


When designing the gating system, it is necessary to prevent the metal liquid from impacting or flushing the core at the front and reducing the erosion of the gate inflow. Try to avoid the gate, overflow trough, and exhaust trough close to the guide post, guide bushing and core-pulling mechanism to prevent metal liquid from entering.


The die casting analysis software application of the die casting mold contributes to the design and layout of the gating system and the drainage system. Through CAE mold flow analysis, it is possible to analyze whether the design of the gating system is reasonable, analyze the balance of the mold temperature and the existence of thermal stress, and analyze the position of the defect and the cause of the die casting defect. According to the analysis results, the casting system is modified to effectively improve the mold design and product quality level.


(2) Demoulding mode selection


Under normal circumstances, after die-casting, the die-casting part remains on the side of the movable mold during the parting. In order to smoothly release the die-casting part without damage or deformation, the correct and reasonable demoulding method should be selected according to the structural characteristics of the die-casting part, and the position and size of the pushing part and the resetting rod should be determined.


For complex die-casting parts, after one ejection operation, when the mold cannot be completely demolded, two or more demolding mechanisms should be used, and the number of times and the structure and sequence of the multiple demouldings should be determined.


The side of the side of the die casting shall be a side core pulling mechanism. The side core pulling mechanism should be selected on the basis of economy and practicality. If the product batch size is not large, a simple side core type can be used; if the manual core pulling mechanism and the movable core core are used, the core can be manually removed after the mold is opened.


When the side core pulling mechanism driven by the mold opening force or the external force must be borrowed, after calculating the core pulling force, an appropriate side core pulling mechanism can be selected and the size of the main structural member can be determined.