Week 9 - Challenge 3 - Bumper

BUMPER DESIGN CHALLENGE

AIM

Create the Bumper Plastic component from the given Class-A surface and find the correct tooling axis and create the draft analysis to check whether the part is manufacturable.

INTRODUCTION

A bumper is a structure attached to or integrated with the front and rear ends of a automobile, to absorb impact in a minor collision, ideally minimizing repair costs.

A bumper is a structure attached to or integrated with the front and rear ends of a vehicle to absorb impact in a minor collision, ideally minimizing repair costs. Stiff metal bumpers appeared on automobiles as early as 1904 that had a mainly ornamental function. Many developments in materials and technologies, as well as greater focus on functionality for protecting vehicle components and improving safety have changed bumpers over the years.Pedestrian safety is also major need for bumber.

CLASS A SURFACE

In automotive design application THE Class A Surfaces are created on all visible exterior surfaces.It is the part with asthetic fearures (ex; body panels, bumper, grill, lights etc.) and all visible surfaces of see-touch & feel parts in interior (ex: Dashboard, seats, door pads etc.).This surface has 0 mm thickness.

Fig 1 Bumber Class A Surface

Fig 2 Bumber Class A Surface

Next is the most important step in this process

FINDING TOOLING AXIS

Tooling axis or tooling direction is main consideration for plastic part and mold parts because it defines movement of mold part and possibility of plastic part to come-out from mold part (Core and Cavity).

So we need to align the part in different directions and check whether the part is completely visible. Try it in X Y and Z directions.So we find the X axis to be better. THen fix X asis as tooling axis .

We tentatively draw a point and line from it from the surface,and draft analysis is done on the part.

Fig 3 Tooling axis for Class A Surface

DRAFT ANALYSIS

Draft analysis is done after determining the tooling axis, draft analysis is used to check whether the minimum draft (3 degrees) is maintained or not.

The Draft Analysis allows to easily analyze a part for proper draft angle and whether it is manufacturable or not.

Here the part have passed the analysis because it is having minimum draft angle of 3 degree

Fig 4 Draft analysis for Class A Surface.

CONSTRUCTION OF CLASS B SURFACE

In this challenge we are using another method for creating class b sufrace from the class a surface.The surface of the bumber is a complex sufrace with fillets and irregular surface.

So we will be moving with another method.Here direct offset method is used.The class A surface is directly offsetted. So we will be getting a surface with some patches unfilled.

The surface is then repaired by splitting the surface into two and the working on the patches by extracting it and extrapolating it and making intersections and then trimming the surface. Then proper fillets are provided.

The steps used are

• extract the surface
• extrapolate the surface and make intersection
• Trim the surface and fillet it.

Fig 5 Offseted surface to make class B surface

Fig 6 Class B surface repaired for patches

Fig 7 Final Class B surface repaired.

CONSTRUCTION OF CLASS C SURFACE

C surface is the surface that joins class-A and class-B surfaces. Class C is often specified for interior surfaces not readily visible.

we cannot simply create the class-A boundary curve and sweep it at one shot. Hence, we need to create smaller curves using multi-extract command and then create sweep .

We need to provide sweep command seperately for the surfaces.

The sweep provided will be two types

• Using drafting direction
• Using referencr surface

We need to use drafting direction when the surface is perpendicular to tooling direction.

We need to use reference surface when the surface is parallel to tooling direction.

To check it, we need to just extrapolate and check with the tooling axis.

Fig 8 Sweep for surface 1

Fig 9 Sweep for surface 2

Fig 10 Sweep for surface 3

Fig 11 Sweep for surface 4

Fig 12 Sweep for surface 5

The sweep surface length is increased so that proper intersection is made is trimmed to form a single surface and joined with the class A surface

Fig 13 Sweep surface

Fig 13 Sweep for surface joined

Fig 13 Sweep for surface joined with Class A

Then the final trim is created by trimming joined surface with class B surface.

Fig 14 Final trim surface

Fig 15 Final trim surface

Fig 16 Final trim surface

Then the part is converted to a closed surface by using closed surface from the part workbench

Fig 17 Closed body surface surface

DRAFT ANALYSIS

Draft analysis is used to check whether the product is manufacturablr or not.and also to check the draft angle of the surface.

The minimum recomended angle is 3 degree.

Here the surface passes the test with 3 degree ,but the 2.5 degree is taken to aviod the failing of surface in c surface.

Fig 18 Draft analysis of Closed body surface

Fig 19 Draft analysis of Closed body surface

Fig 20 Draft analysis of Closed body surface

TREE STRUCTURE

Tress sturcture of the part is shown below

Fig 21 Tree structure of the bumber part

Fig 22 Tree structure of the bumber part

Fig 23 Tree structure of the bumber part

Fig 24 Tree structure of the bumber part

Fig 25 Tree structure of the bumber part

Fig 26 Tree structure of the bumber part

Fig 27 Tree structure of the bumber part