Week 8 - Challenge 6 - Core & Cavity Design
Core and Cavity Design
Objective:
The main objective of this challenge is to create the Switch Bezel Plastic component through the above-given Class-A surface, by giving the 'Tooling axis' , 'Draft analysis', 'Core and Cavity Design' to the Switch Bezel.
We should keenly observe and study the class A surface to create the 'Tooling Axis' for the component, for the above-given base bracket Z-axis is the best suitable tooling axis. Initially, I created a Reference tooling axis on Z-axis by considering the reference point created in the middle of the circle.
Initially Mark up in Z Direction of Reference Tooling Axis
Tooling Axis
CLASS B SURFACE:
To create the class B surface, I considered the entire surface has 3 parts 'Upper, Walls, and Base surface'. If we directly offset the class A surface, fillets may lead to cause an error, to avoid the errors we need to extract the surfaces and untrim the extracted surfaces and extrapolate those untrimmed surfaces with point continuity. Now trim those extrapolated surfaces to the required shape. And finally, fillets were given to the final trim.
Given Thickness Value 2.5mm Offset each Following Components
Class C Surface:
It is the combination of Class A, Class B and Class C surfaces. To create a class C surface, I used the sweep command by considering the outer boundary of the class A surface. In the sweep command, go to the 'line' command in the 'profile' block and the subtype is 'with draft direction'. Now select the outer boundary and tooling axis, give 3 deg in the angle (the draft angle for a plastic component is 0.5 to 3 deg) and select the direction to sweep, in this condition the class B surface is under the class A surface so select the inside down arrow to sweep. The same procedure is repeated for the two circles on the class A surface. Now I joined all the sweeped surfaces by using the 'join' command and then I trimmed the Class A, Class B and Class C surfaces to make a closed surface, to make a Solid body.
Surface A and C Joining
Final Triming of A,B and C Surface
Draft Analysis
The draft analysis technique is used to analyze whether our part model created in CAD is manufacturable based on the draft condition applied. Here the part should get easily removed from the panel dies (in case of Sheet metal part) or Mold (in case of plastic).
No parts can be ejected from the tool if it is having a straight 90-degree profile from its base surface. A small draft angle is provided to each and every area of the component in order to get easy removal of the component from the tool.
Here we are providing a direction in which components should eject in order to get easy removal of components from the tool. In other words, it also lets us know whether the model is having a draft angle and how much is the draft angle from the tool direction.
To perform draft analysis, click on Insert >>Analysis >> Feature Draft Analysis
Once the draft analysis toolbar is opened, go to the display block and select the 'Analysis under the running point' command to check the angle for different sides (ribs and inclined plane angles) on the class A surface. The color scale on the bottom visualizes, whether the draft angle meets the requirements or not (3 deg) by indicating the colors Green, Blue and Red. Once the draft angle analysis was done, we need to align and fix the compass to the tooling axis of the Soild Surface.
Core and Cavity:
A core is the one part of the mould.and it is respponsible for half of the molded part. actually core is the projection of the bodyand cavity is the depression of the body. these core and cavity combines to form a mould. then the plastic material injected into these mould to get a plastic part.
Core Design
Cavity Design
The cavity is the part where the injector and filling of the molten plastic happens. The cavity block is prepared by trimming extrapolated B surface and same profile used in core for rectangular block to extrude along the tooling direction.
The achieved surface is filled and joined to create closed surface as shown picture
Core and Cavity Design:
The mold core and cavity are shaped sections in either half of the mold tool which give the plastic product its final shape. The hot molten material is injected into the core and cavity and then sets hard into shape. The design of the core and cavity is essential in the correct formation of the product. The sequence of events during the injection mold of a plastic part is called the injection molding cycle. The cycle begins when the mold closes, followed by the injection of the polymer into the mold cavity. A core is usually made of the best quality sand and is placed into the desired position in the mold cavity. Core prints are added to both sides of the pattern to create impressions that allow the core to be supported and held at both ends
Intersection of All Core, Cavity & the main componenet are:
Conclusion
Core and Cavity blocks for the Switch Bezel have been successfully created