Week 11 - Project - A pillar Design with Master Section

Aim :

       To create the A Pillar Design with the master section given as the intersection sketch with the Class A surface and create the tooling axis and perform the Draft analysis for the final solid part.

Objective :

• Create the required Tooling axis by using master section.
• Design the Class-B and Class-C surfaces and close all three surfaces.
• Design the Dog house and its internal parts as given Drafts and mater section sketch.
• Draft analysis for the final solid part and side core Draft analysis.

Tooling Axis :

      Class-A surface is first analyzed to create the tooling axis or tooling direction that molds pull apart in injection molding. Tooling direction is important for plastic product design as it decides direction for mold seperation.

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.

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.

Class A Surface:

 TREE STRUCTURE:

CREATE THE MAIN TOOLING AXIS:

 Since we have a Master Section provided to us using which we have to create the desired A-Pillar Plastic Component, We'll use that Master Section by extracting the lines as shown below and create a Bisecting Line with respect to those extracted lines to create our Main Tooling axis.

Draft Analysis of Class A Surface:

The analysis is done with 3 degree draft angle. As we can seen all the surfaces in green colour are 3 degree or more than 3 degree.

At the region shown below the draft angle is lower than 3 degrees but only by a small amount.

  We communicate this development with the Class A Surface Designer and request them to recreate this region so that it'll clear properly with the Main Tooling Axis but for now we're going to continue with this Class A Surface. 

CLASS B SURFACE::

Create a B surface at an offset of 2.5mm with respect to the A surface given. We can notice that few of the elements will be missing after offset. Using features like the extract, extrapolate, multisection etc, fill up the missing elements.

The B surface will look as below after following the above procedure.

CLASS C SURFACE:

• For creating Class C surface we have extracted the boundry from Class A. 
• Now this boundry is sweep along the draft direction with a 3deg draft. 

JOINED OR TRIM OF CLASS B & C SURFACE :

DRAFT ANALYSIS OF CLOSED BODY USING MAIN TOOLING AXIS:

  

CREATION OF ENGINEERING FEATURE- DOGHOUSE USING THE MASTER SECTION:-

Using Master Section we created a sketch that can be extruded to create the doghouse's walls as shown below:

DRAFT ANALYSIS OF DOG HOUSE

Green Colour stands for regions where the Draft Angle is more than 0.5 degrees,

Blue Colour stands for regions where the Draft Angle is between 0-0.5 degrees, &

Red Colour stands for regions where the Draft Angle is lower than 0 degrees

It is evident from the above images that the Draft Analysis is successful and the A-Pillar with the Doghouse is feasible to manufacture.

FINAL BODY

Finally, using the Boolean Operation,  we added the Doghouse to the Closed Body of the A-Pillar as shown below:

3D VIEWS OF THE FINAL PART WITH PROPER COLOR CODE OF THE DRAFT ANGLE IN VARIOUS ORIENTATIONS:

1. FRONT VIEW:

2. TOP VIEW:

 3. ISOMETRIC VIEW:

THANK YOU

AMIT KUMAR