Improve mold design efficiency of automobile parts with ZW3D hybrid modeling

By William Li, ZWSOFT Technical Engineer

1 Introduction

Automobile manufacturing is seeing a rapid development in the industry and an ever rising competitive market. The shape of the car’s plastic interiors are more and more complex and changes are coming faster compressing the product development cycle. One way of reducing the costs of product development is with the use of advanced CAD/CAM integration technology software.  ZW3D is a design tool that integrates product design, sheet metal, reverse engineering, product assembly, mold development and numerical control processing in one package. ZW3D’s unique hybrid modeling technology in mold design can greatly shorten the development cycle, improve the quality of the die, reduces the cost of the mold in development and production processing, producing an economic benefit for the entire enterprise.

The cooling grill is an important part of the car; the modeling is complex and the overall size is large. Using traditional mold design methods, the lead time for ordering material is greatly compressed by the time spent in parting, splitting the insert and electrode design. ZW3D’s hybrid modeling technology, which is built into the product, along with a collaborative design environment allows the part manufacturing process to start earlier and improve work efficiency.

2 Analysis of the status of the mold design

2.1 Most 3D CAD design software does not have specific plastic mold design modules.  They have the basic components of general modeling.  The details of the cooling hole design are done one by one making its operation efficiency low. A few special injection mold design products have a fixed template design process. The corresponding complex plastic die part designs are not flexible and practical enough.

2.2 The mold design process in software is strict; you must follow: product analysis, parting, detailed design, electrode design and material order.  Every station has to wait their turn.

3 The explanation of ZW3D hybrid modeling technology

ZW3D hybrid modeling not only supports solid and surface modeling, but it’s really solids and surfaces working seamlessly together.  The surface data can work with solid data as free and flexible as flipping a light switch.  Make a design follow your idea!

As shown below the car bumper panel is a surface and a solid, the purpose is to get the groove shape.

3.1 The traditional 3d software design method

The traditional 3D software can’t use solids and surfaces interoperability to get the right result.  It must handle the bumper panel and recessed solid individually, to get the inside surface of the open hole through explode, delete and suture, then sew these two surfaces to let them become an independent surface.

3.2 ZW3D hybrid modeling design method

ZW3D supports the bumper panel surface and the recessed solid working with each other directly.  You only need to use a Boolean operation, to add, remove or intersect shapes, to get the results you really want.

So ZW3D hybrid modeling is not just solids and surfaces working in the same environment but real seamless integration working with each other in a single design to provide more flexible and diverse ways of making your ideas a reality.

4 Hybrid modeling in the application of parting

As shown in the figure, if you want to import the car’s cooling grill to make the mold design, due to the design defects or different data translator formats, the geometry will have gaps or open edges; in other words, not water tight.

All traditional software will require a lot of time to fix the dirty product defects. For a particularly complex product model, if you want to get a totally perfect solid, it can take at least a day or a few days to complete it.

ZW3D provides special repair tools, but more impressive is allowing you to use this defective model for parting. Using ZW3D mold design, we can give the fixing job to other engineer, and mold designers can continue parting.

Another way is that using the requirements of the cooling grill tolerance of 0.02. You only repair 52 open edges of more than 0.02 gap, and the other 312 open edges can be ignored. With ZW3D’s unique hybrid modeling, integrated with the ability of solids and surfaces operating seamlessly, you can accept such defective models and still make parting geometry.

5 Hybrid modeling in the application of splitting core & cavity

The general procedure of parting is to create: parting lines - parting faces - split core & cavity regions, which is the most common surface parting principle. The parting line determines the core and cavity area, segmentation, generation of the outer parting faces and internal shut-off faces.  The open surfaces combined with the core & cavity surface areas are used to trim the insert.

But it always gets an error using the traditional software for parting because of the gaps in the surface.  Failure to form a closed surface area makes it unable to cut.  You can’t move forward, you must turn back to check and repair the product model and ensure that the geometry is perfect.

ZW3D hybrid modeling in the parting process has good tolerance, fully supports trimming using open surface and close solids and easily gets cavity and core parts.

The inside of the cooling grill has a lot of irregular cooling holes. ZW3D hybrid modeling handles this situation well.  There is no need to spend a lot of time in creation of the internal parting surface for cooling holes.  We can complete the outside parting surface and the core cavity with blank extremely quickly, and then find the size of the material to order.  At the same time you can add a mold base and purchase it.

Similar cooling grill molds which use a huge amount of steel and non standard mold bases, the cycle time for ordering is very long which often shortens the amount of time for design, but the problem can be solved easily using ZW3D.

6 Hybrid modeling in the application of electrode design

For this cooling grill product, the cooling holes straight walls cannot be finish by machining.  Electrode processing is required.  Most of the time spent in the software is creating parting faces, split shape, and then get cavity & core region.  After that the job can go to programming engineers for electrode design and material order. But ZW3D still can split the part cavity and cores; no time wasted waiting for complete cooling hole parting face; you can instantly submit to programming engineers to order materials and electrode programming. Once part processing is completed, immediately go to processing EDM; the waited time is almost zero, to realize you’re your collaborative design.

7 Conclusions:

ZW3D hybrid modeling technology can easily create the parting faces for new or existing target parts.  It is completely compatible with the assembly mode that mold design requires.  In a collaborative design environment there is no need to wait for core parts to be finished before moving on in the process. ZW3D can do the entire mold process with great flexibility.

ZW3D hybrid modeling technology can not only improve the mold design efficiency, but also has great performance in product design through CNC machining.