Design Principles of Injection Molding for Automobile Molds and Improvement of Processing Performance

Automobile mould injection mainly includes a concave mold with variable cavity, which is composed of a concave mold combined base plate, a concave mold assembly and a concave mold combined card board. It also includes a punch with a variable core, which is composed of a punch combination base plate, a punch assembly, a punch combination card board, a cavity cutting assembly and a side section combination plate. The coordinated change of mold convex, concave mold and auxiliary molding system can process automobile mold plastic parts of different shapes and sizes.

Ⅰ. Design principles of injection molding for automotive molds

1. Clear

The structural principle of the automobile mould is clear, the function of the parts is clear, and there is no omission and repetition. The design requirements of each part should be standardized and optimized (the design basis should be unified, the nominal size should be an integer, and each part cannot be arbitrarily designed).

2. Simple

The injection molding design of automotive molds should be simple and reliable in structure, easy to process and assemble. The simple benefit is a direct cost reduction. For example, the geometry of the part should be simple, the machining surface and the number of machining times of the part should be minimized, and the assembly relationship and adjustment measures with the relevant parts should be reduced or simplified (the relevant parts should not be interfered).

3. Stable and reliable

The injection molding design of the automobile mold should have sufficient strength and rigidity, and the continuous operation of the automobile mold will not cause problems, which is convenient for the maintenance of the mold. The product ejection and demolding mechanism is stable and reliable.

4. The product has high forming efficiency and good quality

If the cooling rate is high, the molding cycle is short, and the pressure of the gating system is balanced, the designed mold can easily remove the runner and gate after the plastic part is formed.

Ⅱ. How to improve the processing performance of automotive molds?

Automotive molds need to improve the processing performance, which is mainly reflected in the following aspects:

1. The increasing size of automotive molds and the high productivity of parts require one mold with multiple cavities, resulting in increasingly large molds. Large-tonnage large molds can reach 100t, with hundreds of cavities and thousands of cavities per mold. The mold processing equipment is required to have a large worktable and increase the Y-axis and Z-axis travel. The mold has large load-bearing, high rigidity and high consistency.

2. The hardness of the mold material processed by the automobile mold is high. The mold processing equipment is required to have thermal stability and high reliability.

3. For automotive molds with complex cavities and multi-functional composites, with the complexity of the shape of the parts, the design and manufacturing level of the molds should be improved. Multi-functional composite molds with various grooves and materials formed in a set of molds or assembled into components require a large amount of processing programming programs, high comprehensive cutting ability and high stability of deep hole cavities, which increases the processing difficulty.

4. The refinement of automobile mold processing makes the composite of processing equipment more attractive. Many advantages, such as stable processing, small cutting force, and small heating and deformation of the workpiece, make mold enterprises pay more and more attention to high-speed machining.

5. High dynamic precision. The staticity introduced by the machine tool manufacturer cannot reflect the actual processing situation during the three-dimensional surface processing of the mold. The high-precision machining of three-dimensional curved surfaces of automotive molds also puts forward the requirements of high dynamic precision performance. High-speed and high-precision can only be achieved with the high rigidity, thermal stability, high reliability and high-quality control system of the machine tool.

6. The combination of processing technology and green product technology will take into account factors such as radiation of electric processing machine tools and medium selection when purchasing equipment.

7. The composite application of various measurement technologies, high-speed measurement and reverse engineering have become the development direction of promoting automotive molds to participate in product development and design technology.