Week 9 - Attachment Feature Creation - Challenge 2

AIM :- To Create the Dog House for the Door Trim considering the design rules.

GIVEN :-

The thickness of the part to be 2.5 mm.

CLASS A SURFACE –

The A-surface or the styling surface is first checked for any gaps and other issues in its surfaces. This Surface acts as the input surface so any correction to be done should be with approval from the styling team or done by them. A- perfect surface is the one when a boundary is created, the lines are only on the edges of a component.

CREATION OF TOOLING AXIS –

Tooling axis is the direction in which a core or cavity of mold opens. This Axis is very important to determine the orientation of the component in mold, core and cavity design.

The tooling axis is created by taking line normal to class A surface.

DRAFT ANALYSIS ON CLASS A SURFACE –

Draft analysis of the surface is carried to check if the surface or part can be manufactured with the required draft angle.

Draft angle is needed for the component to clear the core and cavity surface as it would have shrunk towards the center while cooling.

The draft angle in this design is 3 degrees. As A surface is a single surface there won't be much difference in color. The draft analysis of A-surface is shown below.

From above draft analysis we noticed that all surface area is clearing required minimum draft angle (3 degree).

CREATION OF CLASS B SURFACE :-

For creating class B surface we have to offset class A surface by 2.5 mm. The offseted surface is shown below.

While offsetting the class A surface , some surface area are not get offset. For this missing area we have to use some surface creation feature such as fill , extrapolate , Trim etc. The final class B surface is shown below.

CREATION OF CLASS C SURAFCE –

The A and B surfaces are connected by another single surface which is called the C surface.

It is created by using sweep with A surface acting as the reference surface and curve created from the boundary of the same surface.

Sweep with draft direction is also used to create C-surfaces.

The class C surface is shown below.

CREATION OF CLOSE BODY -

All the surfaces (A,B,C) are joined together to form a closed body.

CREATION OF DOG HOUSE :-

General guideline for design of dog house –

"C" is where the doghouse contacts the backside of the surface

• Doghouse wall thickness at the intersection of the part wall ( C ) should be 40% or less than the main wall stock ( T ).
• The height of ( B ) should be between 3.0 – 6.0 mm

The following steps are used for creating dog house –

First I have create a plane for positioning of dog house.

Then I have drawn sketch on this plane for dog house.

Then I have swept this sketch in tooling direction by 21mm.

Then I have trimmed upper face of dog house by a plane.

Then I thicken This surface body by 2 mm.

After that I split inner area and give 0.5 degree draft also edgefillet of 0.25mm.

And finaly I have given outer surface edgefillet and we get final dog house.

Similarly, I have created second dog house and assmebled with main door trim component.

DRAFT ANALYSIS ON FINAL COMPONENT :-

The following image shows the draft analysis of component from cavity side.

The final solid part body has to be analyzed using Draft analysis. This is done to check if all the areas of the body are satisfying the draft angle which is 3 degrees.

A draft angle is a taper applied to the vertical walls of the injection-molded component to assist with releasing the part from the mold.

Draft angles are a required feature of injection-molded custom parts. A functional part for injection molding has to have draft angles that face both the cavity and core sides. This will reduce the risk of damage to the parts and ensure that they can be ejected from the machine.