注塑模具设计CAD/CAE集成英文文献和翻译(4)
2.4 Module for mold modeling (core and cavity design and design all residual mold components; module IV).
This module is used for CAD modeling of the mold (core and cavity design). This module uses additional software tools for automation creating core and cavity from simulation(reference) model including shrinkage factor of plastics material and automation splitting mold volumes of the fixed and movable plates. The structure of this module is shown .
Additional capability of this module consists of software tools for:
Applying a shrinkage that corresponds to design plastic part, geometry, and molding conditions, which are computed in module for numerical simulation.
Make conceptual CAD model for nonstandard plates and mold components.
Design impression, inserts, sand cores, sliders and other components that define a shape of molded part.
Populate a mold assembly with standard components such as new developed mold base which consists of DM-E mold base and mold base of enterprises which use this system, and CAD modeling ejector pins, screws, and other components creating corresponding clearance holes.
Create runners and waterlines, which dimension was calculated in module for calculating of parameters of injection molding and mold design calculation and selection.
Check interference of components during mold opening, and check the draft surfaces
After applied dimensions and selection mold components, user loads 3D model of the fixed (core) and movable (cavity) plate. Geometry mold specifications, calculated in the previous module, are automatically integrated into this module, allowing it to generate the final mold assembly. Output from this module receives the complete mold model of the assembly as shown. This module allows modeling of nonstandard and standard mold components that are not contained in the mold base.
3 Case study
The complete theoretical framework of the CAD/CAE-integrated injection mold design system for plastic products was presented in the previous sections. In order to complete this review, the system was entirely tested on a real case study. The system was tested on few examples of similar plastic parts. Based on the general structure of the model of integrated CAD/CAE design system shown in Fig. 1, the authors tested the system on some concrete examples. One of the examples used for verification of the test model of the plastic part is shown in Fig. 6.
The module for the numerical simulation of injection molding process defines the optimal location for setting gating subsystem. Dark blue regions indicate the optimal position for setting gating subsystem as shown.
Based on dimensions, shape, material of the case study product, optimal gating subsystem location, and injection molding parameters (Table 1), the simulation model shown was generated.
One of the rules for defining simulation model gate for numerical simulation:
IF (tunnel, plastic material, mass) THEN prediction dimension (upper tunnel, length, diameter1, diameter2, radius, angle, etc.)
Part of the output results from module II, which are used in module III are shown in Table 1.
Material grade and material supplier Acrylonitrile butadiene styrene 780 (ABS 780), Kumho Chemicals Inc.
Max injection pressure 100 MPa
Mold temperature 60°C ili 40
Melt Temperature 230°C
Injection Time 0,39 s 0,2 s
Injection Pressure 27,93 MPa
Recommended ejection temperature 79°C
Modulus of elasticity, flow direction for ABS 780 2,600 MPa
Modulus of elasticity, transverse direction for ABS 780 2,600 MP
Poision ratio in all directions for ABS 780 0.38
Shear modulus for ABS 780 942 MPa
Density in liquid state 0.94032 g/cm3
Density in solid state 1.047 g/cm3