[1]
Entity repair method. By creating an entity in the cavity area, then selecting hole edge block for the clip and realizing entity patch, it specifies the entity is to fill in the surface of the core or cavity, the plastic pieces has eight entities to be repaired.
Google Scholar
[2]
Boundary repair method. By selecting a border to fix open areas, the several holes of this plastic pieces can be repaired through choosing a closed boundary surface , this plastic parts has 4 boundaries to be repaired.
Google Scholar
[3]
Existing surface repair method. It needs to use the method of modeling to create Patch Surfaces for irregular and open surface of the cavity edges, then defined these Patch Surfaces as repair surfaces. After completion of the repair operation, it can use the"segmentation" method of molding to separate the core area from cavity area, and validate by MPV. Through extracting areas, the number of core surfaces is 262 and cavity surface is 353, and these surfaces are equal to the total of surfaces. It Indicates the operation of segmentation" is successful, that is undefined surfaces number is zero, then we can get the final parting line. The parting line of the model is a more complex closed curve, so using the way of "automatically create" can not form parting surface. It's necessary to create transitional object, which refers to some dots or lines of the product parting line, and the parting line are divided into several sections by these points or lines. We can respectively adopt the different ways to define for each segment. Through stretching and scanning to form parting surface. Finally, by"suturing"operation to get a complete parting surface. Generating the parting surface is shown in Fig. 4 , and the cavity and core shown in Fig. 5. Fig. 4 The last parting surface Fig. 5 Cavity and Core The Mould Base Design Using UG mold design section can be integrated 3D design and assembly of the die structure. This paper chooses the standardly series of SA type of Japan FUTABA. It belongs to "3535 mould base", which is 350 mm×350 mm. Selecting the GP_d of Guide pillar is 30 mm in diameter, the U_h of bearing plate is 60 mm, and the CP_h of block is 70 mm. According to the strength and rigidity conditions, respectively by choosing a rectangular composite cores to make U_h conform to the requirements, and the height of validation block also satisfies the requirement of mould at last. After setting the mould base, it also needs to set up and build the cavity for ejector mechanism, gating system, cooling water, etc. Taking the position of plunger for Instance, With ejector is set as an example, through calculating plunger diameter is 6 mm, distribution form, and the distribution of cooling water need to consider the balance of ejection device, as shown in Fig. 6. Fig. 6 Ejector distribution and mold base Core and cavity NC processing The plastic parts of core and cavity are complex. Because it have many narrow grooves at the bottom of insert , it is hard to being processed with tool. Therefore, we can Simplify the processing model with the synchronous modeling method of "delete surfaces" in UG. Getting into NC the machining module of UG and setting the technological process , specific it as follows: firstly, choosing the blank geometry, and determining the machining area, then selecting the methods and tools, machining allowance and the route of tools. After that, the module of UG CAM can generate the G code of NC machining and then transmit it to the CNC machine. It can greatly reduce the workload of programming operators. However, the generate G code need to be proceed in postprocessing, that can be general utilization and customization. Finally, it, s converted into the G&M code, which can be received by the numerical control machine. Conclusions.
Google Scholar
[1]
UG parametrization model can effectively help designers improve the structure of plastic parts and simplify model of NC machining.
Google Scholar
[2]
The article uses a variety of model repair methods to solve the complex problem of the plastic parting , and it has a certain reference value for model parting.
Google Scholar
[3]
Based on the integrated technology of CAD/CAE/CAM, and combined with the numerical simulation of injection molding and the mold design method of MV. Finally, we can obtain the best parameters of molding process, then it's better to complete the integrity of die structure design. It optimizes the scheme of mold design, reduce the development cost and guide the actual production greatly. References.
DOI: 10.3139/9781569906903.017
Google Scholar
