(3) Reasonable selection of the parting surface of the mold
According to the shape and structural characteristics of the die-casting parts, it is an important part of the mold design to determine the parting surface reasonably. The choice of the parting surface largely affects the complexity of the mold structure. Parting surface selection principle:
1) The parting surface is simple and easy to process.
2) It is beneficial to simplify the mold structure.
3) The accuracy requirements of die castings should be easily ensured.
4) The parting surface should be suitable for filling and forming.
5) Keep the die casting on the side of the movable mold as much as possible when opening the mold.
(4) Structure and size of parts
According to the properties of the die-casting alloy and the structural characteristics of the die-casting part, the specific pressure of the injection is determined, and combined with the projected area of the die-casting part and the depth of the cavity, the calculation and determination are made:
1) the thickness of the sidewall of the cavity;
2) the thickness of the support plate;
3) Determine the thickness of the cavity plate, the movable platen, the movable plate seat plate, the fixed mold seat plate and related dimensions;
4) determining the position and main dimensions of the mold guiding form;
5) determining the positioning mode, installation position and fixing form of the die-casting mold;
6) determining the connection and fixing form of each structural member, and combining the various structural members into one body;
7) Determine the mold temperature adjustment method, and arrange the position and size of the cooling or heating pipe.
For more complex molded parts, it is important to consider the actual processing method, whether it is a common processing method or a special processing method. When the traditional processing method must be adopted due to the limitation of processing equipment, it should be considered how to separate and inlay to make it easier to process and polish, and to avoid deformation of heat treatment to ensure the dimensional accuracy of assembly.
The accuracy of the relative moving parts should be considered in consideration of the influence of the mold temperature change. Appropriate movement tolerances should be selected to achieve smooth, flexible and reliable movement in a die-casting environment with high mold temperatures.
The radial matching precision of the die-casting structure parts, the tolerance matching and surface roughness of various parts are correctly selected, so that the working part does not bite and smash the metal liquid at the working temperature, and the fixed parts are not loosened. Reasonable use of the combination of inserts to avoid sharp corners and sharp edges to meet the heat treatment process requirements. When setting the push rod and core hole, keep a certain distance from the edge of the insert, and the overflow groove should also be kept at a certain distance from the edge of the cavity.
Due to the design of the die-casting part, the inevitable vulnerable parts of the mold, especially the boss core of the smaller cross-section, should be inlaid as much as possible to facilitate replacement when damaged. The mold design should use standardized common parts as much as possible to shorten the mold manufacturing cycle.