Week 9 - Project - Master Section Development

AIM-

To create a solid body of B pillar cover including ribs and locators using CATIA v5 tool using given A-class surface and master section and adding thickness.

INTRODUCTION -

B-Pillar

The B-pillar is the central pillar of the car. This pillar is actually a sheet metal part that is welded in the BIW of the car. The B-pillar trim is attached to the B-pillar and improves the aesthetic look of the car. Mostly the trims are manufactured by the injection moulding process. The design of the B-pillar is carefully done to make the part manufacturable and usable in the interior. While manufacturing a part through injection moulding a lot of defects can occur on the plastic part which will destroy the look of the panel. The design has to make in such a way that all the errors can be rectified.

OVERVIEW OF DESIGN LIFE CYCLE AUTOMOTIVE INDUSTRY

The Stages of the Design Life Cycle are

Concept Sketches-

Concept sketches are rough ideas of freehand sketches obtained through the styling team and will be used to prepare the Model. It is usually done through pen and paper and through the painting software. This is will be used to generate the concept for preparing the model by incorporating various styles and information obtained from the stakeholders

Class A Creation-

After finalizing the concept the sketches are usually worked in software such as Autodesk, ALIAS to create Class A Surface

Clay Modeling -

The Class A Surface is concurrently worked by clay modellers to brainstorm and benchmark the styling of the product and later the Concept is validated by bringing up a rough clay model and then it is passed on to the Design team for the preparation of New Product Design (NPD) CAD.

NPD CAD -

This is where the development of surfaces to parts in CAD kick-off and the Design engineer's involvement is vital in this stage.

The Designers will work on the Input Class A surfaces which are validated by the Feasibility team

The procedure followed in the creation of the plastic New Product Design are

Tooling Axis
B Surface Creation
C Surface Creation
Closed Body Creation
Draft Analysis

Input-

Tooling Axis-

- Check the Connectivity of class A Surface: these can be done by creating boundaries or by joining command if there are any gaps or openings they will be easily visualized.

-Visually analyse the best possible tooling axis.

-the clearance checking along all the axis on the plane with the model and constructing two lines in contact with the walls, the line bisecting the two lines and passing through the point will be the tooling Axis.

but for this cat part, the bisecting method is not required because every part of the cat can be cleared throw the Z direction only easily.

The tooling axis is nothing but the direction in which the core and cavity open and close. The design engineer works are to analyse the Class-A surface and find out the best possible tooling direction keeping in mind all the draft angle is with respect to the tooling axis so that the component can be easily ejected from the moulds.

Class A surface-

In automotive design, a class A surface is any of a set of freeform surfaces of high efficiency and quality. Although strictly, it is nothing more than saying the surfaces have curvature and tangency alignment – to ideal aesthetical reflection quality, many people interpret class A surfaces to have G2 (or even G3) curvature continuity to one another. Class A surfacing is done using computer-aided industrial design applications. Class A surface modellers are also called "digital sculptors" in the industry. Industrial designers develop their design styling through the A-Surface, the physical surface the end-user can feel, touch, see etc. and the class A surface is created in the software called ALIAS.

Draft Analysis on Class A surface-

A draft analysis compass is used to define the draft direction.

check whether the minimum draft of 3deg  is assumed or not. the minimum draft of 3 deg is provided with the whole component changing

into green colour.

In some parts of the Class-A surface is not clearing the draft analysis this should be reported to the class-A team.

Updated Class-A surface-

updated with the  Flange using the given multi sections as the reference.

 

Class B Surface Creation-

Represent internal and/or functional surfaces. This cluster exemplary includes derived surfaces created by offset operations from class A surfaces to define the thickness of the material (2.5mm). In this file, it is important to link class B surfaces geometrically to enable an adaptation to class A surfaces automatically in case of styling change.

After creating the tooling axis, a B surface is to be created which is nothing but the surface parallel to the A surface. B surface contains all the fillets and the edges which the A surface contains.

 Updated class-B surface-

Class C Surface Creation-

Class C Surface is swept along the boundary of Class A at an angle perpendicular to the CLASS A surface with respect to the tooling axis direction with a draft angle of 3 degrees.

Joining CLASS A, B and C Surfaces to get Closed Surfaces-

After finishing all the 3 surfaces, join the class A and class C surfaces together using the Join command. Now, the joined surfaces are then trimmed with a class B surface to form a closed surface.

Making of the solid part using the class surface command-

after the completion of joining the class A, B, C surfaces ensure that the surface has no gaps between then using the boundary command if it did not form the boundary then the surface is closed switch to the part design and insert the new part body and use the close surface command to get the solid part.

Creation of Ribs and Dog house And 4-way locators-

4-way locators mean you prevent movement at 2 axes (+X, -X, +Y and -Y) on the plane. Generally, you have a cylindrical pin on the fixture and a circular hole at the workpiece part.

In any kind of assembly before fixing the part to the mating part we need to fix the position of the part with respect to the mating part. In these cases, we need to follow some engineering principles. In this project, we are going to follow the 3-2-1 Principle. Any Part which has to be fixed during the welding or machining process has to be fixed is having 12 degrees of freedom.

Translation Movement along X-Axis
Translation Movement along Y-Axis
Translation Movement along Z-Axis
Rotational Movement along X-Axis
Rotational Movement along Y-Axis
Rotational Movement along Z-Axis
Dog House :

Create the dog house as per the design rules and give the required draft angle.

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

DOg house with 4way locator-

Ribs-

Rib design-

Ribs are used to strengthen the walls of the mould without increasing the overall wall thickness.it is an economical way to increase the stiffness of the component.

they help in-

Locating and arresting components of an assembly

providing alignment in mating parts

acting as stops or guides for mechanisms

ex- headlight

design rules to follow while cretin the ribs-

Draft Analysis-

The Draft Analysis command enables you to detect if the part you drafted will be easily removed. This type of analysis is performed based on colour ranges identifying zones on the analyzed element where the deviation from the draft direction at any point, corresponds to specified values.

Draft angles are very important in thermoforming product design. If the product is formed onto a female or negative mould, it shrinks away from the mould sidewalls. As a result, true female or negative products can be thermoformed with vertical walls having zero draft angles.

 Draft analysis for the final output-

Draft Analysis of A-side-

Draft Analysis of B-side-

In some parts of the Class-A surface is not clearing the draft analysis this should be reported to the class-A team.

Side Tooling Axis for the Dog house-