Week 12- Final project
Development of a Door Trim panel
AIM :- To create a CAD model for door trim panel's parts by considering the given inputs of class A surface along with master section by following the design rules followed in OEM and tier1 companies.
Objectives :-
* To create individual tooling axis for the parts and perform draft analysis on the class A surface
* To create the class B and class C surfaces from the given class A surface
* To form a solid geometry by combining all the surfaces
* To decide an attachment strategy for the part and create engineering features in reference from the master section provided
* To perform draft analysis on the solid part model with all engineering features
* To assemble all the components togehter to obtain the final trim
Given Data :-
Class A Surface for Door Trim Panel -
As we know in automotive industry there are complex products that we have to design but this is not possible with simple sketches for that we need 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 and its holes or cutouts as shown below.
Steps Follwed for Completion of Project :-
The door trim panel is created by follwing steps -
* To check given Class A surafces for any modification.
* To segregate given surafces into separate part body namely Lower Substrate , Arm Rest , Map Pocket , Bottle Holder.
* To work individually on each part.
* To create tooling axis for part.
* Draft analysis on class A surafce.
* Creation of class B and Class C surafce.
* Craete closed body from Class A , B and Class C surface.
* Follwed same procedure to craete all parts .
* Then create attachement features for all parts.
* Then do Draft analysis on final parts and then constrain them for assembly.
ARM REST
Class A Surface -
A . Check Given Class A Surafce for improvement
CLASS A is not good in that particular area so we have to inform our styling team to iprovement and also remove some extra surface from class which can create problem in creating close surface as we already know that the class a is not manufacturable the patch that I removed is shown in below picture
So you can see in above pic that the small patch I removed and after that I got the below surface
B . Improvement of Class A Surafce -
As shown in above image I have improved given class A surface in surafce workbench by using surafce operation such as extract, extrapolation , trim etc.
* Creation of Tooling Axis
tooling axis creation using point direction method
DRAFT ANALYSIS USING THIS TOOLING AXIS
From the draft analysis we can see that the class a surface is not clearing the minimal draft of a 3 degree in with this tooling axis ,
So I have to check with another tooling axis ( using normal to surface method )
So you can see that I create this tooling using normal to surface method, ok lets check the draft analysis
from the above picture you can see that still the draft is not clearing preperly , ok lets try a another method of create tooling axis ( using bisecting method )
From the above pic you can see that I create a tooling using bisecting method
Lets do the draft analysis
And we need a sidecore also to get the desired mould of a arm rest as you can see in below fig I create a side core aslo
As we know that there are three types of tooling creation methods are using in any industry ( point direction , bisecting , and normal to surface , ) So I analise the draft of CLASS A with help of all tooling axis But some portion is not clearing the minimal draft of 3 deg ,
So from that I understand that the CLASS A dosn’t have the proper draft so I have to inform the CLASS A designer to improve the CLASS A
Creation of Class B Surface -
Class B surface is created by offseting class A surafce by 2.5 mm as per the mastersection. After offseting some area not get offseted , there patches formed. This patches are closed by surface creation features such as fill , multisection , blend etc.
After offseting there are some patches come in b surface as you can see in the below fig
After improving all patches from clss b I got the exact class b as shown below
* Creation of Class C surface -
C surface is the connecting surface of Class A and Class B surface. By using Sweep we created the Class C surface. For that first we have to extract Class A boundary and then with draft direction at angle 3 degree we have sweep the class A extracted boundary. And we get the Class - C surface.
Creation of Closed Body of Arm Rest - By trimming join of Class A ,C with Class B surface we get close body.
Solid Body of Arm Rest -
Creation of Flanges on Arm Rest -
From mastersection we get the idea of flanges . I have created flanges on Arm Rest by considering counterpart (Lower Substrate) position.
Draft Analysis on Soild Body of Arm Rest -
DRAFT : The draft is something that allows the componenet to release or eject from the mold properly. The draft is required on all parts in the direction of mold movement in order to allow parts to release properly. Most parts or applications require a minimum of 1/2 to 1 degree, however , 3 degrees is widely accepted as the norm.
The draft is given in the direction of tooling direction or core cavity opening.
If we don't give the draft to the component it strick to the mold and friction alos act so we get the damage in our part so to overcome this we give some draft angle to overcome this problem.
As mentioned above we have two tooling axis for Arm rest.
Following images give the idea about is it manufacturable or not.
CLASS B :-
CLASS A :-
From above draft analysis we notice that given part is not as good to manufcature. There is lot of modification needed. We have to request styling team to improvement in class A at particular areas.
So I crate the flange for arm rest but it clashing with lower substract uou can see in below fig
This is because as we already know that the class a of a arm rest is not manufacturable and also I remove some patch from that particular portion
This side patch
that’s why its clashing with lower substract
MAP POCKET
Class A Surface -
Check Given Class A Surafce for improvement
* Creation of Tooling Axis
* Draft Analysis on Class A -
From above draft analysis we noticed that all surafce have minimumm 3 degree draft.
Creation of Class B
Class B surface is created by offseting class A surafce by 2.5 mm as per the mastersection. After offseting some area not get offseted , there patches formed. This patches are closed by surface creation features such as fill , multisection , blend etc.
After ofseting somr patches form on class b surface so I have to fix them
Improved CLASS B
Creation of Class C
C surface is the connecting surface of Class A and Class B surface. By using Sweep we created the Class C surface. For that first we have to extract Class A boundary and then with draft direction at angle 3 degree we have sweep the class A extracted boundary. And we get the Class - C surface.
Final Solid Body of Map Pocket
Creation of Flanges
From mastersection we get the idea of flanges . I have created flanges on Arm Rest by considering counterpart (Lower Substrate) position.
You can see from this below fig that the flange that I create completely follow the mastersection
Draft Analysis on Final Body
CLASS A:-
CLASS B :-
From above draft analysis we say that map pocket is manufacturable. All The a surface and b surface is clearing the draft of 3 deg and b side features are also clearing the draft of 0.5 deg bur some area in c surface not clearing the draft of 3 deg but it only have 0.9 deg draft in that particular area shown in fig below
BOTTLE HOLDER
Class A Surface
Check quality of Class A
It looks like the class a is completely fine
Creation of Tooling Axis
Tooling creation using point direction method
Check draft analysis using this tooling axis
So I can see that there are lots of area is not clearing the draft of 3 deg ( in below fig )
Ok lets Check with another tooling method
Tooling creation using Normal to durface method
Check draft analysis using this tooling axis
In this process also the surface is not clearing the minimal draft of 3 deg
lets check with bisecting method
Still the class A is not clearing the minimal draft so from that I understand that the class A does not have the proper draft so I have to inform the class A designer to improve the class A
Creation of Class B
For creating Class B surface we have to offset it by 2.5 mm upward as shown in above image.
Creation of Class C
For creating class C surface we have to use sweep feature of surface creation.
Class A and c join
Solid Body of Bottle holder -
Creation of Flanges
For creating the flange of a bottle holder there is no mastersection was given , so I can create this flange following plastic deesign rule
Class A
Class B
From above draft analysis we noticed that bottle holder part is not as per requirement. It is not manufacturable because at some area it have negative draft for that we have to informed styling team.
LOWER SUBSTARCT
CLASS A
Creation of Tooling Axis
Drfat Analysis on Class A
From above draft analysis we say that given class A is of good quality. All area have minimum 3 degree of draft.
Creation of Class B
Class B created by offseting class A by 2.5 mm.
Creation of Class C
Creation of Solid Body
CLASS A
CLASS B
From above draft analysis we noticed that all the area have minimum 3 degree of draft.
Creration of Heat stake
HEAT STAKES -
Heat stakes are used in thermoplastics to assemble two parts together by locally heating and cooling the plastic material and allowing it to reform itself and act as a joint for the two materials.
We have placed 9 heat stakes in the model based on the reference points created by estimation.
One of the important factor to be considered while designing the heat skates is the height of the heat skates. It should always be less than the height of the locators.
Drfat Analysis on Heat Stake -
Creation of Locators
LOCATORS -
The main purpose of locators is to facilitate proper locking of two components together while assembling and arrest the maximum degrees of freedom possible.
These locators are similar to guide pins provided in mould.
The two types of locators used are two way locator and four way locator.
We have positioned three 4 way locators in our model which meet the rib design criteria.
Draft Analysis on Locators -
All the faces of locators have minimum draft 0.5 degree.
Creation of Dog House
DOG HOUSE -
The two main purposes of a dog house are to avoid sink marks and to house various other engineering features like screw boss, locators, push clips etc.
In this case, the dog house is designed to house the push clips and the 4 way locator. The dog house designed for the push clip features a slot on the top face to accommodate the push clip
The dog house should follow certain design rules which are stated below
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
Outer surface of dog house must have a draft angle of 3 degrees
Inner surface of dog house must have a draft angle of 0.5 degrees
Draft analysis for dog house
Outer portions clearing draft with main tooling and we need to analyse the inner area draft using side tooling
Ok lets analyse the draft of whole b surface and b side features of a lower substract
Al the b side features clearing the draft of 0.5 deg that means all the b side features are properly drafted so now I have to assemble the push pin on top of the dog house like shown below
FINAL ASSEMBLY
CONCLUSION :- so the dorr trim development is done with maintaining the plastic design rule