CAE DS – Mould and Die Design Exercises Parting Surface 3 Tampere University of Technology – Tuula Höök
Theoretical background −
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CAD tools in the exer‐
cise parting_3_3.sldprt Mould structure Basic features in the injection molded or high pressure die cast part: draft, corner rounding, parting surface and undercut. Steps to follow Take the SolidWorks part (start_parting_3_3.sldprt) or one of the neutral format models. Scale the part and prepare a parting line, shut‐off surface and a parting surface. Make a tooling split. 1.
Scale the part. The scale factor depends on the plastic or metal alloy in use. Decide which material to use and find a suitable value. 2.
Prepare the parting line with the tool provided in the software. If the part is designed with proper draft in right places, the software usually chooses the parting line position automatically. Parting line is positioned to the level of changing draft angle di‐
rections. Draft angle analysis is part of the SolidWorks parting line tool. The first step in using this tool is to select the pulling direction and to make the draft analysis. Draft analysis shows the draft angle directions with colors. There should be one uni‐
form color in the core side and one uniform color in the cavity side. The parting line follows the part outer surface in the edge of the changing color. Parting line tool creates normally two sur‐
face bodies: One surface into the folder named “Cavity Surface Bodies” and another to the folder named “Core Surface Bodies”. See that the box “Use for Core/Cavity Split” is ticked. In this ex‐
ample part you need to take one additional step to create the shut‐off surfaces to close the holes in the part before the cavity and core surfaces are ready. 3.
Mold −
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Scale Parting Line Shut‐Off Surface Parting Surface Tooling Split If there are problems in using these tools, open SolidWorks help and try to find the solution there. Prepare a shut‐off surface to the opening in the middle of the part. Tooling split tool needs three uniform surfaces: One to form the mould core side, one to form the mould cavity side and one to form the parting surface. If there are holes in the part walls, the core and cavity surfaces are not uniform. The shut‐off surfaces close the holes and complete the core and cavity surfaces. They are positioned to the level of changing draft direction as did the parting line. Typically the software finds the right shut‐off surfaces automatically if the part is properly drafted. After this operation you should have one surface body in the folder “Cavity Surface Bodies” and one surface body in the folder “Core Surface Bodies”. Parting_Surface_3_3 ‐ 1 CAE DS – Mould and Die Design Exercises 4.
Prepare a parting surface with SolidWorks surface tools. The part shape is rather complex, but the parting line is a simple circle, which allows the modeler to use SolidWorks tools. Figure 1:
Basic shapes in the parting surface. It consists of one planar rectangular surface and two curved surfaces. 5.
Prepare a tooling split. Start by sketching the mould or die workpiece outlines to the parting sur‐
face. The software should find all necessary surfaces from the folders “Core Surface Bodies”, “Cavity Surface Bodies” and “Parting Surface Bodies”. If not, locate the surfaces manually. Tool‐
ing split creates three separate solid bodies: One is the original part, one is the cavity side of the mould (or die) and one the core side of the mould (or die). It is not necessary to take the work‐
piece dimensions from any real core or cavity plates. You are able to model the pieces further in any desired way. Learning Objectives −
Basic tools for creating the parting of the mould or die for a part with complex shapes. CAD tools to learn − Mold: Draft analysis, Scale, Parting Line, Shut‐off Surfaces, Parting Surface, Tooling Split Evaluation criteria Accepted − Finished tooling split with the listed tools Excellent − Finished tooling split with the listed tools − Material is chosen. The scale factor is chosen according to the material data. Parting_Surface_3_3 ‐ 2 CAE DS – Mould and Die Design Exercises CAD tools quick guide With this tool collection you can draw the shapes that are used as starting points in other tools. Sketch Insert Æ Molds Æ Scale Scales the part with a given factor. You are able to give one single factor or separate factors to x, y and z directions. Insert Æ Molds Parting Line Places the parting line to the corner where draft angles change direction. If there is no such corner you may show and/or define the corner by yourself, but it is quite likely that in this case the part is not moldable or castable. Parting_Surface_3_3 ‐ 3 CAE DS – Mould and Die Design Exercises Insert Æ Molds Æ Shut‐Off Surface Creates surfaces to close holes inside the parting line. Shut‐off surface completes the core and cavity surfaces for the tooling split tool. The holes in the part should have corners where drafting changes direction. That is the corner to place the shut‐off surface. The corner for placing the shut‐off surface should be sharp like the corner for placing the parting line. Insert Æ Molds Æ Parting Surface Creates the parting surface between the core and cavity side of the mould or die. The tool uses the parting line as a starting point. You can also define the parting surface manually. If the parting line is complex, it is usually necessary to prepare the part‐
ing surface with the SolidWorks surface tools, knit the sheets together and place into the Parting Sur‐
face Bodies ‐folder inside the Surface Bodies ‐folder. Insert Æ Molds Æ Tooling Split Creates mould or die core and cavity halves as separate solid bodies. The tool uses the surfaces placed into the Core, Cavity and Parting Surface Bodies –folders. Parting_Surface_3_3 ‐ 4