Week 8 - Challenge 6 - Core & Cavity Design

Aim : To create a core and cavity block for a switch bezel design using catia v5 and perform draft analysis .

objective :

The objective are as follow :

• To create class B and class C surface from given class A surface.
• To perform draft analysis .
• To create core and cavity .
• To create parting line.
• To create parting surface.
• To create report of it .

Introduction :

• It is the fram part of the window switch that holds its switch cover and button place.
• Moulding is the method used to manufacture the plastic trims of an automotive by OEMS.

Class A surface :

• It is surface os asthethic look .

Class B surface :

It is for engineering purpose .

Class C surface :

It is a surface which joins class A and class B surface .

Design consideration :

Tooling axis creation :

• First the surface is checked for any irregularities .
• First the base surface of class A is extracted and point is created at the centre and axis system is also created at that point .
• now using project intersection command , intersection of class A and yz plane is created .
• Now sketch command is used and drawn two lines coincides with interction .
• now using bisection command line is created which bisects the two lines.
• Now in xz plane there is only one surface so we have drawn a line having around 6 degree of draft angle .
• Now tooling axis is created by bisecting above two lines.

Given class A surface

Lines created in skectech and then by intersection method :

Final tooling axis :

Creation of class B surface :

• Following procedure is followed for vrersting class B surface .
• First the using extract command to extract base , wall and surface .
• now untriming it.
• now using extrapolation command .
• now ofset it at 2.5 mm distance which is thickness .
• now untriming the surfaces .
• finally fillet is created by meaure the fillet values of class A surface and giving the fillet value of radius minus the thickness .

Extraction :

Untriming :

Extrapolating :

Triming :

Fillets :

Class B surface :

Class C surface :

• Boundry of outer edge of class A surface is extracted and to avoid patch we have use curve smooth option .
• by using sweep command the surface is created .

Extruction:

Sweep :

Final ClassC surface :

Closed surface creation :

• by using close surface command the close surface solid body is created .

Creating core and cavity design :

parting surface :

• injection oulding has two component movable half and the fixed half .
• During injection process, these halves are pressed tightly from a sealed hollow to avoid the melt flow leakage and maintain cretain holding pressure , the pressed surface is callled parting surface .
• It is the projection outline of the part .

Parting line :

• it is an ineitable part of injection mould product.
• It is the line of seperation between where two halves of a mould meet .
• It is created by triming class A surface join with class C surface with class B surface and using intersection command .

Core :

• It is part of mold which goes inside a cavity to form the interior of a hollow part.
• To create the core part , create rectangle and extrude it alog the tooling axis .
• now trim it and make solid body .

Cavity :

• It is other half side of the mold.
• repeat the same procedure to create cavity .

Below is the picture shows the core , cavity , parting surfance and parting line :

Different views :

Isometric view :

Front view :

Side view :

Top view :

Procedure for draft analysis :

• First class A surface is check for draft analysis then final product is checked .

Steps :

• first we have change the view mode to custom view parameter in which select material.
• then activate compass and placed it alog with tooling axis and then locked it.
• Now click on the surface.
• It shows the green colour which means that it pass draft analysis which has angle of 3 degree which sufficient enough for manufacturing of the product .

Class A :

Final product :

Different views :

ISometric view :

Front view :

Top view :

Side view:

tree structure :

Publication :

COnclusion :

• We have created class B and class C surface from given class A surface .
• Created core and cavity.
• PArting line and parting surface .
• performed draft analysis.