Challenge

Week 12- Final project

SSidhartha Sankar Sahu19 Apr 2023

AIM : Development of a Door Trim panel considering inputs , such as

a) Class A surface
b) Nominal thickness : Refer master sections
c) Attachment strategy

Use Push pin with Dog house for Lower substrate – Door panel attachment

Use heat stakes for part to part attachment

REPORT :

strategy for the project :

step 1: creation of components from given class-a surfaces & master sections.

step 2 : creation of b side features for each components from given master section.

step 3 : assemble b side features with its respective componets and represent every component with its b side features in the product workbench with attachment strategy.

- creation of components from given class-a surfaces & master sections :

WHAT IS TOOLING AXIS : The direction in which the mold or core and cavity opens is the tooling axis.

HOW TO CREATE A TOOLING AXIS :

1) Before creating a tooling axis , as a preventive measure check the Connectivity of Class-A surface. it can be done by using the "join" or "boundary" command. using these command we can identify any unnecessary openings of the class-A surface.

no unnecessary openings are found.

2) visually analyse which is the best possible way to create the tooling axis , considering avoiding side cores, easy ejection of component from core, easy flow of molten plastic inside the cavity.

tooling axis along 'x' & 'z' is impossible here , and considering the flat surface in the number plate area , 'y' axis is perfect for tooling axis.

tooling axis creation using Bisecting method :

As per its name , in bisecting method we bisect lines which are along the class a surface walls which we think might create an issue while manufacturing , as the result of the bisection we get a line which clears each and every sub surface of the class a . and we consider the line as tooling axis for the component.

but for this surface there are multiples walls to consider , that is why we are performing along axis method . as we can clearly see along 'y' axis the class a is completely visible , but not along 'x' & 'z' , so we will create tooling axis along 'y' direction.

- extracted a flat surface along 'y' axis .

- created a point in the middle of the surface .

- using point-direction command created a line / tooling axis on that point along 'y' direction.

- then to confirm the tooling axis is clearing every surface of the class a or not , performed draft analysis.

Draft analysis :

After determining the tooling axis , Draft analysis is done.draft analysis is used to check whether the desired draft angle is maintained or not. Compass is used in the draft analysis command to define the draft direction. as an output of this operation , we will be receving a colored range table , which will clearly show which surface of the component is getting cleared or not with the required draft angle , and with that result we can modify the surface.

Draft analysis for class-A :

every surface is clearing with 3 degree draft angle .

Draft analysis for final plastic component :

necessary surfaces are clearing with 2.9 degree draft angle .

creation of final component from class-A surface :

Created a class-b surface from class-A surface by first offseting the class a with considering the master section thickness , as a result got a surface with some unformed fillets and unformed surfaces . using extrapolate and multisection like commands , created a good quality class b or repaired the unformed offset.

Then created class-c from class-A by first taking the boundaries from class a then sweep them along tooling axis & class-b and then combined the sweeped walls /class c with the class-A surface.

Finally trimmed the extrapolated class-b with class a+c to get the final drafted surface for the component/part. and then using close surface command in the part workbench , converted the final trim in to a solid.

similarly performed the above steps for the creation of arm rest :

map pocket :

bottle holder :

- creation of b side features for each components from given master section :

heat stakes and its supporting ribs creation :

what is heat staking and why we use them :

Heat staking is the process to attach two separate components together by melting the base plastic material into a shape that will hold the secondary component. It’s a permanent attachment method that does not require any additional material such as an adhesive or a solvent to make the permanent bond. The only addition is the heat applied to melt the plastic and a tool to shape the plastic to form the mechanical connection.

- all the components is going to attach with the lower substrate with heat staking in between heat stakes of lower substrate and flanges of respective components .

- created multiple points for heat stakes , and then created heat stake and its supporting ribs by sketch and then in the part workbench converted the sketches in to solid by using pad command and drafted them , unitrimmed the heat stake with the supporting ribs and provided required fillets.

- and finally using point to point trasnslation , situated the heat stakes in every points created earlier.

sketches for heat stake and supporting ribs :

pad and draft operation :

for places where the heat plate can not go for heat staking , in those places created locators for attaching.

dog house :

Doghouse is an engineering element used in the creation of plastic trim. Dog kennels are used as auxiliary elements. In order to increase their strength, snaps, locators, and other engineering features are occasionally mounted on them. Draft analysis is applied to dog houses to prevent component breakage during component ejection from the mould cavity.

design rule for dog house :

-Doghouse wall thickness at the intersection of the part wall ( C ) should be 40% or less than the main wall stock ( T ).

-Height of ( B ) should be between 3.0 – 6.0 mm

dimension of the dog house :

- using sketch , pad , unitrim and draft created the dog house for push pin assembly

flange creation :

For attachment of components with the lower substrate we need flanges , flanges will have a counter hole for the heat stake , and the flanges will rest on top of the heat stake supporting ribs , after the heat staking process the counter hole will fill with liquid plastic and solidify at the spot and that way we can get a permanently attachment.

flanges will start from the c surface , according to the master section created a sketch for the flange by first taking an extract from c surface , making an plane .

after that sweeped the sketch with the extract boundary of the c surface .

created a line then extruded the line along z direction and created two offset outof the extrude , for the flange .

using thicken command in the part work bench , thicken the sweep with master section requirement.

splited the solid with the two offset created earlier.

drafted the split with 0.5 degree with the main tooling axis.

finally created a counter hole in the part , and then removed that from the flange and gave fillets to the flange.

created multiple flanges for every component and assemblem them together .

assembled all the parts in the product work bench .

finally imported the push pin into the product work bench , and assembled it to the each dog house using axis coincidence and offset constraint.

- Draft analysis & tooling feasibility :

for lower substrate :

class a :

final part :

for b side features , heat stakes & locators :

for dog house outside :

dog house inside :

for map pocket :

class a :

final part :

info :

i could have made this clasa c clear with 2.7 degree draft angle , but i choose not to beacuse here as you can see there is no edge , it is a continous surface , so i had to go with reference surface method for both the side .otherwise there was a sharp edge was forming in draft direction method.

b side features , flanges :