Challenge

Week 11 - Final project

GGagandeep Reddy Avula Venkata Mallikarjuna8 Mar 2023

FINAL PROJECT

AIM

To create the Door trim panel's CAD model considering the inputs given to me following the design rules and OEM standards.

ABSTRACT

The project deals with the explanation of steps and procedures followed while developing the Door Trim Panel of a car using CATIA V5. Using the

class A surface I was able to create the tooling axis, class B surface, class C surface, and after forming the solid body from that I was able to

create the flanges and the B side features such as Dog house, push pins, Heat stakes, etc. And finally, the draft analysis is also done on the

components to check the manufacturability of the components.

INTRODUCTION

The door panel will usually match the rest of the vehicle's interior. Door panels were formerly made of cardboard with an upholstered interior finish

vinyl, leather, cloth, carpet, or other materials for the decorative trim. Modern cars typically have door cards made of plastic, most often using

injection molding, as well as incorporating other decorative materials.

The design should incorporate both the necessary service amount and the functional unit (such as "it is strong" and "it looks and feels good") so

that a given car door panel "would service a car body's life span of 200,000 kilometers (124,274 mi)." The door panel typically incorporates other

parts that contribute to the appearance, functionality, and ergonomics of the vehicle. These include armrests, switches, or other controls for

windows and the locking mechanism, convenience lights, Map pockets, lower substrate, storage compartments, and other features. An image of

the door trim panel is shown below

The steps that I followed for this project is mentioned below

--Extracting the class A surface from the input

--Draft Analysis of class A

--Creation of Class B and Class C surface from Class A

--Created the solid body and performed the draft analysis on the solid body

--created the flanges

--Created the Engineering features

--Draft analysis of the component with Engineering features.

PROCEDURE

MASTER SECTION

Master section are the guides for a design that shapes the component after technical styling of class A surface. The Master

section is parameterized model of the vehicle body that outlines the guidelines for the NPD team.

so here I have to create three parts that are mentioned below:

--Lower substrate

--Map pocket

--Door Armrest

Then I have to create the attachment features that are required for the assembly of the parts.

First I have started by creating the lower substrate. For this, I have extracted the class A surface of the lower substrate from the input that is

given. The extract is shown below:

Then I have split the extra portion from the class A surface by creating the line and splitting using the split feature in generative shape design. so

the final class A surface is shown below

TOOLING AXIS

The tooling axis is defined as the direction in which the mold opens or core and cavity opens and closes. The selection of the correct tooling axis is

important to ensure the component is taken out perfectly and also the cost of the component should be less.

I will start by insering a geometrical set and naming it as a tooling direction. For creating the tooling axis I will analyze the model and see from

which direction I can see the whole model. so here the direction I have chosen for the tooling axis is along y-direction because along y-direction

the whole model is visible properly. For creating the tooling axis I will create one point on the lower substrate and from that point, I will create one

line along the y-direction and that line will be my tooling axis.

DRAFT ANALYSIS

Draft analysis is a technique to analyze whether the component created is manufacturable or not based on the draft conditions applied. So here I

will provide the direction in which the component should be ejected to get the easy removal. My dirction will be the tooling axis that I have

created.

The minimum draft value for the Automotive plastic component is 3 degrees and those for the texture faces 7 degrees of the draft is suitable. The

draft is provided to the component for easy removal from the mold in the case of the plastic components.

So here I will change the customize view parameters and will select the material mode.

In the above fig. under the display, the section selects the color scale and turns on the light effect for proper visualization. then under the direction

section, I will click on the compass and will drag the compass from vehicle zero to my tooling axis. and then I will click on the lock feature and will

select the class on the surface. The result is shown below

The Green color denotes that the draft provided is above 2.9 degrees.

The Blue color denotes that the draft provided is between o and 2.9 degrees.

The Red color denotes that the draft provided is negative.

After performing the draft analysis I have made sure that the proper draft is provided on the component and now I can create the further surfaces

which are class B and Class C surfaces.

CLASS B SURFACE

It is a surface that gives thickness from a class A surface. All the supporting features of the component will be formed on the B surface only. so we

can say that Class B is an engineering surface and Class A is an aesthetic surface.

For creating the class B surface I have offset the Class A surface to 2.5 mm which is the thickness of the part according to the master section that

is given as the input.

CLASS C SURFACE

Class C surface is defined as the surface which connects the CLASS A and CLASS B SURFACE along the tooling direction. The tooling direction here

will be my tooling axis.

For creating Class C I have extracted the boundaries of the class A surface and swept the extract along the draft direction. giving a 3 degrees

draft. Also, I have used the smooth curve feature to smoothen the swept surfaces. Here I have also used the reference surface option in sweeping

for the portion that does not require a sweep with draft direction. The sweep parameters are shown below

Then I have joined the sweeps that I created and if some sweep is extending I have trimmed it according to my requirement to get the class C

surface. The final class C surface is shown below

After this, I have created a solid body from this closed surface by using the close surface feature in part design. The solid lower substrate is shown

below

Now after creating the lower substrate I have created the map pocket

For the map pocket, I have divided it into two parts one is the inner map pocket and the other is the outer map pocket.

OUTER MAP POCKET

First creating the outer map pocket following the same procedures as I did for the lower substrate. So extracting the outer map pocket surfaces

from the input. The multiple extracts are shown below which is also the class A surface for the outer map pocket.

TOOLING AXIS

For creating the tooling axis again I have created the point on the surface and from that point, I created a line which is the tooling

axis for the outer map pocket. The tooling axis is shown below

Now the draft analysis on the class A surface is sown below

CLASS B SURFACE

Now for the class B surface again I have just offset the class A surface to 2.5 mm. The offset is shown below

CLASS C SURFACE

For creating the class C surface I have taken the boundary of class A and class B surface and blended them together. Before blending them

together I have given smooth curves to the boundaries of A and B. The blend is shown below

I got the part but it was not a closed boundary or closed surface so to resolve that issue I have taken the intersect between class A and Blend and

another intersect between the class B and the class C surface. After creating the intersection I have split the class B and the intersect of B and C.

same I have done for the c surface as well and the similar thing I have done with the intersection of A and C is have split the A surface with the

intersection of A and C. Finally I have joined the splits together to get the part with a closed surface.

DRAFT ANALYSIS

INNER MAP POCKET OR BOTTLE HOLDER

For creating the inner map pocket again I have followed the same procedures as I did before. So extracting the surfaces that form the inner map

pocket.

After multiple extracts, the surface I got was a class-A surface of the inner map pocket. The class A surface is shown below

TOOLING AXIS

For creating the tooling axis I have followed the same procedure that is creating a point on the class A surface and creating a line from that point

along the direction in which class A is clearly visible.

CLASS C SURFACE

For creating the class C again I have swept the boundaries of class A using the 'with reference surface' option in the sweep command. And I have

swept the boundaries to 87 degrees with the reference surface of the boundaries. The sweep parameters are shown below

--Then I have joined the Class A and Class C surfaces

--Then I have trimmed the join of A and C with class B surface after extrapolating the class B wherever it's required

--After creating the part I have checked the surface whether it is closed or not by taking the boundary on it. It showed an error that means the

surface is closed.

--Then I have just created the solid part from this closed surface using the closed surface command in part design and also i have given it a color.

The solid part is shown below

Then I have performed the draft analysis on the solid part. The draft analysis is shown below:

After creating the solid parts for the lower substrate and map pocket I have created the door armrest. For Door Armrest again I have spilt the part

into two parts and named it according to me one is the door armrest cushion part and the other is the door armrest.

ARM REST

For this again I have to first extract the class A surface from the input given. The multiple extracts are shown below:

After extracting the surface I got the class A surface but there was a gap. so I filled it with the multisection surface

TOOLING AXIS

For the tooling axis, I have created one point on the base surface and from that point, I have created one line along the direction in which the

component is clearly visible. For the door armrest part, two tooling axis is required one is the main tooling axis and other is the slider tooling axis

because the main tooling axis cannot clear the component alone.

The main and slider tooling axis is shown below

CLASS B SURFACE

Again following the similar procedure that is offsetting the class A to 2.5 mm

CLASS C SURFACE

For creating the c surface again I have used the sweep command. So I have swept the boundaries of class A along the tooling axis with a 3-degree

draft. And for some parts, I have swept the boundaries using the 'with reference surface' option.

Then finally I have trimmed the join with the class B surface after extrapolating the B surface wherever it's required to get the final part.

SOLID BODY

Then I have created the solid part from this closed surface using the closed surface command in part design. The solid body is

shown below,I have provided the color also to the part.

FLANGES

Flanges are the elements that are needed to join different components together. So here I have to make flanges on the door armrest and the map

pocket. Following the master section, given as the input basically the measurements and location of the flange. I have created the flanges. First I

have created the flange on the outer map pocket. For creating the flanges I have taken extraction of the curve and made a point on that curve

then created one plane on that point followed by creating a sketch on that plane taking the point created as the origin. The sketch is shown below

Then I have provided the draft and fillets to the flange. The fillets value can be taken from the master section master if given or u can provide a

minimum fillet of 1 mm. coming to the draft value here for the outer map pocket I have provided 3 degrees and but if the flange size is less than u

can provide a minimum draft of 0.5 degrees. After providing the draft and fillets the flange looks like this

Then I have copied the flange body and paste it on the main part body using the as result with a link option in paste special.

After pasting I have translated the flange using the point-to-point translation feature keeping in mind the spacing rule that is the gap between two

flanges should be 60 - 100 mm. Then after the translation, I have used the union trim boolean operation to make one single body. The outer map

pocket with flange is shown below:

The same thing I did for the other parts also that is extracted the curves in which the flange is required then I made a point and plane then

sketched on it to create flanges later provided drafts and fillets.

The flanges of the inner map pocket are shown below for this part I have given 0.5 degrees draft to the flanges.

The flanges of the Door Armrest are shown below for this part also the draft is 0.5 degrees

DOG HOUSE

Dog house is an engineering feature used in the plastic trim design. Doghouses are used as supporting features. Sometimes other engineering

features like snaps; locators, etc. are mounded on them to increase their strength. Dog houses are subjected to draft analysis to prevent breakage

of the component during ejection from the mold cavity. Dog house and other engineering components are built on B-surface.

Then I have closed the surface on the top. After closing the surface I have used the thick surface command to make a solid body giving 2mm

thickness. Now for the dog house also it will require an additional axis which is called a lifter axis that would clear the inside portion of the dog

house because it won't be clear using the main tooling axis. so for creating that lifter tooling axis I have created one point on the back surface of

the dog house and from that point created one line and that line is my lifter axis.Now according to this tooling axis, I have drafted the inner

portion of the dog house. the draft value I have given is 0.5 degrees. Actually, I have given the draft before giving the inner fillets and that is the

correct method to do it later u can give fillets.

For this purpose, I have just offset the base of the lower substrate to a height of 4mm the value could be anything between 3 - 6 mm. and then I

have extracted the inside portion of the dog house. The offset and extraction of surfaces are shown below.After trimming I have the trim to 1 mm

considering the design rule that it should be 40 % of the thickness of the component. The thickness of the component is 2.5 mm so 40% of 2.5 is

1mm. After offsetting it to 1mm I have split the offset surface with the dog house body. the split is shown below:

DRAFT ANALYSIS

Then I have done the draft analysis on the dog house. The draft analysis considering the main tooling axis is shown below:

Here the tooling axis is my lower substrate tooling axis

Now we can provide the fillets. so the dog house is completed.

Next, I have created the push pins.

PUSH PINS

Push pins are used for joining one component to another. These are basically attached to the dog house.

For creating the push pins I have taken the following reference basically the measurements.

Then I have made the cut out on the dog house for inserting the pin. For the cut out I have made one sketch on the top surface of the dog house

and extruded it. The extrude is shown below

Then I have split the extrude from the dog house to get the cut-out. The cut out for the push pin is shown below

Then I have just added using the boolean operation to my dog house. The dog house along with push pin is shown below:Then I have used the

copy and paste special option and translated the dog house along with a push pin to different locations on the lower substrate in which I want the

dog house. so basically I have created points on the lower substrate and used the point-to-point translation. After doing the translation I have just

added all the dog houses to the lower substrate.

HEAT STAKES

Heat staking also known as thermoplastic staking is the process of joining two dissimilar materials together. In heat staking, we use local heating

and cooling to raise the temperature of plastic components and allow plastic reforming to be carried out. This reforming can be used in a wide

variety of applications.

Applications range from staking plastic bosses for assembly of car door panels to joining PCBs to plastic housings. Benefits of this technique

include; no vibration damage, no particulates, the ability to stake metalized coated applications, and the capability to stake in difficult to access or

restricted areas.

The progressive melting of plastic under continuous pressure forms the head. When staking the right combination of heat and pressure for the

application is critical.

The advantages of Heat staking are as follows:

--simplification of the machinery

--Reduced cost of machinery

--Multiple fastening points

--Allows higher density of welds compared to hot air cold form or ultrasonic welding.

Before creating the heat stakes I have created the holes on all the flanges that I created earlier. For the hole, I have created one point on the

upper face of the flange and created a sketch on it.

Then I have thickened the offset surface to get the solid body. The thickness value was 2mm and provide a draft of 0.5 mm. The thick surface is

shown below: