Week 8 - Challenge 6 - Core & Cavity Design

AIM :

To create the Core and cavity blocks for the switch bezel which we have designed in the earlier challenge.

THEORY :

DRAFT ANALYSIS :-

The Draft Analysis command enables you to detect if the part you drafted will be easily removed. This type of analysis is performed based on color ranges identifying zones on the analyzed element where the deviation from the draft direction at any point, corresponds to specified values.

PARTING SURFACE :-

Generally,injection mold has two major components : the movable halve and the fixed halve , during the injecction molding process, these two halves are pressed tightly from a sealed hollow to avoid the melt flow leakage and maintain certain holding pressure, the pressed surface are called parting surface , usually parting surface are the biggest projection outline of the part.

Parting surface design principles :-

Parting bsurface design directly affects the product quality , ease of construction and opearation of the injection mold , the mold design is one of the key facctors to success.

Principles to follow to design Parting surface :-

1. Design the injection mold simple as possible .Avoid or reduce side parting as much as possible to reduce complexity of the mold making.
2. Ease of de-molding as far as possible, for instance the plastic parts should stay in fixed halve of injection mold and should ejected by ejection system avoid , side de-molding action,
3. Ensure the dimension accuracy of the molded parts ,Try to make the parts similar dimension accuarcy reqirements in same mold to reduce manufacturing and assembly errors .
4. Ensure apperance reqirement of molded parts,finish or mismatch usually occurs on parting surface , so the parting surface should not be designed on high quality requiremnent surfaces.
5. Ensure adequate venting.If possible parting surface should be place at the end of the mold flow.This is going to be advantage of fillng and venting.

PARTING LINE :-

Part lines are where the two halves of the mold meet. This generally creates a physical line on a part that is both visible and noticeable to the touch. These lines, however, can be hidden or minimized when placed along edges of the part. When designing a part, always keep in mind its part lines.

FEATURE TREE:-

DESIGNING CORE AND CAVITY:-

• PROCEDURE :

When you look at the part we have designed the color highlighted region side is the core side since it have the projections .here we are extrapolating the class A so that we can use it for trimming purposes while creating core and cavity blocks .if we can observe from draft analysis we have done on this component in the previous callenge the A surface and C surface had tooled along A side i.e., "main tooling axis" direction.

1)CAVITY DESIGN:-

so we are considering it as a part of core .for creating core we need untrimmed class C and class B surface which we created before .here we are trimming class B with extrpolated class B.

2)CORE DESIGN:-

CLOSE SURFACE:-

Close surface command is used to make the solid body from the surfaces.

Intersections:-

Here we will use intersection beween x plane with parting surface and core .the pink color shows the core,yellow is the core where it walls are extruded alom and the blue shows the parting surface which split the core and cavity,always ensure to have parting surface on B side.now lets design the cavity now,we follow the same process as above first we will extrude the surfaces/walls along tooling axis direction ,we ignore the component area and rim the body with b surfaceand then fill the bottom portion to make it closed body for solid block/cavity block.

Parting line is the area in which parting surface and component meets or core half and cavity half meets/juction between the pating surface and the component here we will intersect a and c surafce joined together with b surface so that we will get parting line which is clear splitting line between core and cavity .it is very exact juncyion where core and cavity closes at the parting surface and intersection of the component with parting surface is the parting line.

CONCLUSION:

• The Core and cavity blocks for the switch bezel component is created.