Week 11 - Final project

Challenge -32 Plastic Design Final Project (Lower Door Trim)

Objective: To design the Lower Trim of the door from the given Class-A Surface Catia-V5

Project Overview:

Door Trim isthe interior component attached to the interior side of the door. It 's a vital component which provides aesthetic look to the interior of the car and also provides features and functions for the passengers. In this project we are going to design the lower portion of the door trim from the given Class-A Surface. A surface. Also we would be designing the B-side features on thecomponent by following the Industry standurds and design rules.

workbench and its Toolbar used:

Geneative Shape design workbench

• Surface Toolbar
• wireframe Toolbar
• Operation Toolbar

Part workbench

• Sketch Based Feature Toolbar
• Dress up features Toolbar
• Surface based Feature Toolbar

Theory:

Tooling Axis- Tooling Axis is the direction in which the component will be ejecting after the molding process is completed . The rules of selecting an optimmum direction of tooling axis for any particuler component is as follows:-

• The direction of the tooling axis hould be clearing the maximum number of portions of the component once the molding process is compleated.
• The direction of the tooling axis should be selected such that the number of side cores required should be minimum , as inserting side cores causes a rise in production cost.

Drafting - Draft is the inclination given to any particuler plastic component's cavity walls in order to acheive easy ejection, once the prcess is completed.

• Consider that the draft angle between the plastic component and the core is Zero.
• When the molten plastic inside the cavity cools, it sticks to the core.
• During suchzero draft condition, th ejection of the plastic component causes friction between them which might bring damage to both the core and thecomponent.
• This damage further leads to inefficiency i the production & also effects the product's surface finish.
• Hence, a minimum of 0.5 to 1 Degree draft is provided to help in releasing the component.
• However 3 deg draft is widely accepted as a norm in the industry.

Prerequisites before creating the tooling axis and performing draft analysis-

1. Ensure that the Class Asurface imported should be a single surface.
2. This can be checked using the Boundary tool in the Operation Toolbar.
3. If the surfaces are disassembled , join them using join command which is also found in the operation toolbar.

Creating any component from Class A suface ( Overview)-

1. Deside a suitable tooling axis direction and create the Tooling Axis.
2. Perform Draft analysis for analysing whether the drafts on the component follow the industry standurds.
3. Create another surface (B Surface) offset to the Class-A surface. The offset distance should be equel to the thickness of the component.
4. Create a C-surface 'Sweeping' the boundary of cass-A surface along the tooling Axis.
5. Trim Class-A surface with B-Surface and C-surface to create a close surface.
6. Finally create the solid part from this surface to obtain the desired component.

Procedure:

I] Visual Analysis of Class-A Surfaces:

Firstly we observe the Class-A Surface and Understand how the component can be manufactured.

Observing the Master Sections:

II) Creation of Tooling Axis:

1. Tooling Axis can be decided using various methods, namely-Bisecting Method, Trial and error basis using Draft Analysis Tool or simple 90 degree to the component.

2. In industries, the tooling axis is mainly considered as 90 deg and the Class-A Surface designed according with proper drafts on the componend

3. Wherever necessary the tooling can be modified.

4. For our Component we consider the tooling in Y direction , but for the armrest we have a side core tooling. (The reason for the same is mentioned under the draft Analysis Report.)

III) Draft Analysis of Class- A surface:

• Draft Analysis is performed on the component in order to check whether the compnent can be manufactured or not.
• THis draft Analysis tool in catia allows us to analyze the drafts provided on the surface.
• We can check whether they follow industry standards and if not we can modify it accodingly.

The procedure of Draft Analysis is follows:-

1. Before starting the draft analysis ensure that the 'Materials' option is selected under customize view parameters in order to view the results of the analysis.
2. Click on insert>> Analysis >> Feature Draft Analysis.
3. Draft Analysis window will be opened having three sections- Mode, Display and Direction.
4. IN the Disply section select the composs and drag it onto your component. place it along the tooling axis.
5. Lock the direction of the draft.
6. Another window will be displaying ranges of draft on the component. The ranges are-green for more than zero, Red for zero and Blue fornegitive draft value.
7. Assign the lower limit as 3 deg to the Green rang from the value edition dialogue box.
8. Once you do it, click on the component to see the results.
9. You can also check the draft value at any point using the 'Analysis unde runing point' option in the display section.
10. Minimum DRaft for the component = 3deg

Lower Substrate:

Map Pocket:

Bottom Holder

Note: The patches shown do not clear in the decided tooling diection. This needs to be modified by the Class-A Designer. In industry we have to report it to the higher authorities so the component can be modified accordingly.

Draft here in the red zone is 3 degree inverse and the blue region is 2.38 deg which needs to be changed. we are neglecting it for the further project proceedings.

Arm Rest

• As we can see in theabove imges the car front portion of the arm rest was not clearing in Y-Direction.
• Hence we have used another tooling Axis in Z-Direction in orderto clear that area.
• Also we splitted the component in 2 parts for easy manufacturing.

IV) Designing the solid Component from Class-A:

Note: The representation below of the steps mentioned above are the lower substrate only. similar steps were performed for designing other com[ponents.

Class-A Surface:

B- Surface

Surface C:

Closed Surface:

Solid Body Formed:

Lower Substrate

Map Pocket:

Bottom Holder:

Arm Rest:

V) Designing the B-side Feature and Flanges:

Ribs and Heat stakes:

Heat stakes: It is the process used to join two more parts by deformation of the plastic by applied heat and pressure, for a certain time. The applied heat melts the extruded heat stakes on the primary component and it settles on the secandary component. After cooling both the components are firmly joined.

Draft Analysis:

Minimum Draft = 0.5deg

Ribs: Ribs are the features which are used to provide strenth and stiffness to the component. Rather than increasing the thickness of the whole component providing ribs reduses cost and also serves as guides for assembly of two components wherever necessary.

Design rules for ribs:

1. thickness of the rib = 0.4x thickness of of the component.
2. Rib Root Thickness = + or -30% of thickness of the component.
3. Rib fillet Radius = 0.25mm
4. Draft = 0.5 deg
5. Rib Depth < or = 5x thickness of the component.
6. Height / width ratio = 3:1 or 2:1 (Preferred)

Locaters: Locaters are the features on the plastic component which enables us to arrest the degrees offreedom of the part and helps in fixation of the componen.

The two types of locaters used here are:

• 2- Way Locaters
• 4- Way Locaters

Design Rules for Locaters:

1. Thickness of the Locaters = 0.4x thickness of the component.
2. Fillet Radius = 0.25mm
3. Draft = 0.5 Deg

Note: The height of all the locaters should be equal.

Draft Analysis:

2-Way Locaters

Screw Boss: They are designed for assembly of two components using screws.

Design Rules for screw boss:

1. Outside Diameter = 2 to 2.4 x Diameter of hole
2. Step distance = 1.5 mm
3. Distance of screw penatrated into the component < or = 0.3 x Thickness of the component.

Dog House: Many times the screw bosses or push pins need to be given extra length in orser to perfectly assemble with other components. We can't directly increase their height, as all the components are made with prpotion to the width and thickness of the component. This can cause sink marks on the component.Hence we provide a dog house wherever necessary and place our engineering feature above it for perfect finish of the component.

Design rules for Dog House:

1. Sink Saver Thickness = 0.4x Thickness of the Dog House
2. Length of sink saver = 3mm to 6mm
3. Upper width = 12mm
4. Outer Draft = 1.5 deg minimum
5. Draft for Lifter Axis = 0.5 deg

Draft Analysis:

• Draft Analysis of Dog House along g Core Axis

• Draft Analysis of Dog House along Tooling Axis

Flanges:

Flange is a feature Designed for attachment purpose.It has holes in it which us mounting one component on the other and carry out the heat staking process.

Push Pins:

The Push pins mounted on the dog House is a standurd part used in industries. We haven't followed any design rule for designing them in our project.

Draft Analysis of parts

• Lowe Substrate

• Map Pocket

• Bottom Holder:

• Arm Rest

Rendering in Catia V5:

The Rendering Tooli in Catia helps to provide the aesthetic look to the component. We can apply material to our model and present our Component about how it is going to look.

This can be done following the below steps:

1. Click on the "apply material" option.
2. Select the material which you want.
3. Click on the part from the tree structure.
4. Click on the "Apply Material" and "Ok"
5. Further Click on the "Rendor" icon and adjust the environment suitable to your component.
6. Click on "Save" to save the rendered image of your component.

Final Component:

Conclusion:

We have successfully designed the lower trim for the door panel from a given Class-A surface in Catia-V5.