Week 11 - Project - A pillar Design with Master Section

OBJECTIVE: To create the A-Pillar's Plastic component from the given Class A Surface using the Master Section that is provided while following all the design rules.

INTRODUCTION:

Types of Pillars and their Importance in the Automotive Industry:-

These pillars standing at the vertical or near-vertical (slightly inclined) position are structural supports for the car's roof and window areas. 

They are pretty important as they provide a strong foundation to install the glass (windscreens, rear, and side windows) of your car. Also, these are strong enough to hold the entire roof (even with roof racking to carry additional weights).

There are several pillars your car can have, and each has got a name. Pillars are named “A”, “B”, “C”, or “D” (in larger vehicles), if you move from the front to the rear end of your vehicle.

The number of pillars will vary from car to car.

For example, most sedans and hatchbacks will have three (A, B & C) pillars whereas larger cars like SUVs will have all four (A, B, C & D) pillars.

Hardtop structures (often referred to as pillarless hardtops) will have only two (A & C) pillars.

 

ROLE OF THE A-PILLAR:

A-Pillar is located on either side of your car’s front window (or windshield).

They also hold the hinges of your front doors. A-pillars are normally made of steel alloys.

Besides being a supporting member, A-pillars are very crucial as far as safety is concerned. A-pillars usually carry a significant amount of load during a frontal collision or a rollover crash. So the larger the width or cross-section, the greater would be the strength but A-pillars always block the driver’s vision (create blind spots) to some extent that can be realized while driving. So, having that said, using thicker A-pillars can make the situation even worst. It might further lower the driver’s vision and raise a question about the vehicle’s and passenger’s safety.

Hence, the design of A-pillars must be optimized giving equal importance to both strength and the driver’s vision.

 

Firstly, we have to create the required Tooling-Axis for the given Class A Surface while meeting the requirements of the necessary Draft Angle & then perform the Draft-Analysis Operation on the Class A Surface itself.

After that, we have to create the required Class B & Class C Surfaces using which we have to make the Final Plastic Component and perform Draft Analysis on it.

 

MAIN REPORT:

Types of Surfaces and their importance for an Automotive Plastic Designer:

• Class A Surface: Class A is an aesthetic surface with the highest quality finish. Most Class A Surfaces for an Automotive Component are made using 'Autodesk-Alias' based on the final Concept-Sketch. All Class A surfaces should have 'Curvature-Continuity', meaning the continuity between the surfaces should share the same boundary. It is taken as a reference by the Automotive Plastic Designer to create 'Class B' and 'Class C' Surfaces.

 

• Class B Surface: The Class B Surface resides below the Class A Surface at a certain thickness. It is created using Engineering Principles that consist of all the necessary features such as Ribs, Bosses, Snaps, etc. This surface isn't visible to the observer from the outside.

 

• Class C Surface: The Class C Surface is the surface created between the Class A and Class B surfaces to join them with each other.

 

Now, we will begin by checking the State of Connectivity for the Class A Surface and ensure that there are no gaps between the surfaces as all the surfaces should be joined well together with each other and shouldn't consist of any discontinuities between them.

Our Class A Surface:

 

Tooling axis-Bisecting line Method

 

Using a dummy tooling axis, the bisecting line method is essentially used to identify the correct tooling axis. When using the bisecting line method, a line is utilized to either bisect the two lines or indicate an error, indicating that the two lines are parallel. We intersect the surface with the appropriate plane to determine whether or not the surface is toolable. This produces a drawing with two lines, which we can then bisect to produce a third line at the intersection of the two lines.

 

DRAFT ANALYSIS ON THE CLASS A SURFACE:

Next, We will perform a Draft Analysis on the Class A Surface itself:

Before starting with a Draft Analysis Operation, we will go to the 'Customize View Parameters' option under the 'View Toolbar'. Then we will enter the 'Customize View Mode' where we will go under the 'Mesh' option and select 'Material' and press 'OK'. 

 

To start the Draft Analysis in the 'Generative Surface Design Workbench', we will go to 'Insert' and then look for the option called 'Analysis'. Once found, we will go under that and click on 'Feature Draft Analysis. This will open the 'Draft Analysis' Dialogue box. There, we will ensure that under 'Mode'  we have selected 'Quick Analysis', under 'Display' we will select 'Show or Hide the Color Scale' and then select '3 Degrees' as the permissible draft angle. Then, under 'Direction' we will choose the icon with the symbol of the compass on it which stands for 'Use the Compass to define the new current draft direction

POCEDURE TO CREATE THE CLASS B SURFACE:

We'll offset the Class A Surface by 2.5mm as shown below

 

POCEDURE TO CREATE THE CLASS C SURFACE:

 

By taking the boundary of the Class A surface and by using the sweep (reference by surface and with draft direction) method Class C Surface is created

Then join the class A surface to the class C surfaces after that I trim out the joined A and C surface to class B surface to get the final object.

 

Final Surface:

Trimming the Class AC surface with B surface the final surface has been created.

CLOSED SURFACE:

DRAFT ANALYSIS =DRAFT ANALYSIS ON THE CLASS A SURFACE:

DOG HOUSE

Dog house is an engineering feature used in plastic design. Dog houses are used as support feature. Sometimes other engineering features like snaps, locators, screw bosses are mounted on them to increase their strength.

Dog houses are subjected to draft analysis to prevent breakage of the component during ejection from the mould cavity. Dog house and other engineering components are built on the B-surface

• Dog houses are designed to avoid SINK MARK created on the CLASS-A surface by screw bosses and to solve the length issues when giving screw bosses which need to be assembled to other components.

• It is also useful when perpendicular screw bosses are required on the part to the tooling direction.
• Make a rectangle to enclose the screw boss in it but make sure it is open from one side.
• Sweep it with tooling axis as the pulling direction inwards.

• Close the top face by using multi section surface.
• Thicken it by 2.5 mm to the outward direction.
• 

DRAFT:

DIFFERENT VIEW  WITH DIFFRENT COLOURS-