The design of the die structure and the choice of parameters must take into account factors such as rigidity, orientation, unloading mechanism, positioning method, and gap size. The consumables on the mold should be easily replaceable. For plastic molds and die-casting molds, it is also necessary to consider a reasonable pouring system, molten plastic or metal flow state, and position and direction of entry into the cavity. In order to increase productivity and reduce runner casting losses, a multi-cavity mold can be used to accomplish multiple identical or different products simultaneously in a single mold. High-efficiency, high-precision, and long-life molds should be used in mass production.
Stamping dies should use multi-position progressive dies, which can use carbide inserts to improve die life. In small batch production and trial production of new products, simple molds with simple structure, quick manufacturing, and low cost should be used, such as combination punches, sheet punches, polyurethane rubber molds, low-melting-point alloy molds, zinc alloy molds, and superplastic alloy molds. The mold has begun to use computer-aided design (CAD), that is, through a computer-centric system to optimize the mold design. This is the development direction of mold design.
According to the structural characteristics of the mold, the mold is divided into a planar stamping die and a cavity die with space. The punching die is precisely matched to the size of the punch and the die, and some of them are even without clearance. Other forging dies, such as cold extrusion dies, die casting dies, powder metallurgy dies, plastic dies, rubber dies, etc., are cavity dies that are used to form three-dimensional shaped workpieces. The cavity mold has dimensional requirements in three directions of length, width, and height, and the shape is complex and manufacturing is difficult. Mold production is generally single-piece, small batch production, strict manufacturing requirements, precision, and more sophisticated processing equipment and measuring devices.
Plane blanking die can be formed by EDM, then form grinding, coordinate grinding and other methods can further improve the accuracy. Forming grinding can be performed with an optical projection curve grinder, or a surface grinder with a mimicking or repairing grinding wheel mechanism, or grinding with a special forming grinding tool on a precision surface grinder. The coordinate grinder can be used for precise positioning of the mold to ensure precise aperture and hole spacing. It is also possible to grind any punch-shaped punch and die using a computer numerically controlled (CNC) continuous trajectory coordinate grinder. Cavity molds are mostly used for profile milling, EDM and electrolytic machining. The combination of copy milling machining and numerical control and the addition of a three-way translation head device in EDM can improve the machining quality of the cavity. The addition of aerated electrolysis during electrolytic processing can increase production efficiency.