Challenge

Week 8 - Challenge 4 - Bumper

RRajesha Dn30 Dec 2022

Challenge -24 BUMPER DESIGN

Aim:

Creat the Bumper Plastic component through the given Class-A surface. To begin with, the tooling axis for the given Class-A surface should be created meeting the requirements of th draft angle and at the end perform the Draft anaysis on the model.

Introduction:

Creat the Bumper is a structure attached toor integrated with the front and rear ends of a motor vehicle, to absorb impact in a minor collision, ideally minimizing repair costs.

They are designed to absorb impact to the front and rear of vehicles and minimize low-speed collision damage. Today standurd passanger vehicle bumpers have a rigid reinforcing bar under the outer coveer, with sections of compressible foam or plastic undeneath.

A bumper is made up of four parts:

Bumper cover.
The bumper absorber.
The bumper reinforcement bar.
The bumper mounting system.

The first car bumpers were created all the way back in 1901 and onsisted of metal beams attached tothe front and rear ofthe car to protect it during a low- speed coolision. Designed to protect the expensive and fragile components like the headlights, tail lights, hood exhaust, and cooling systems, early metal pumpers were focused on sheer resilience.

Modern consumer production cars have almost compeletely switched ove to plastic bumpers. Modern car bumpers are made from thermoplastic olefins, a blend of plastic molecules,rubber, and a reinforcing filler like carbon fiber or calcium carbonate. This blend of material creates a scratch and impact- resistant plastic that can bond with wide range of paints and finishes, making it ideal for vehicle bumpers.

Platic is the preferred material for modern car bumpers for several reasons. First and foremost, plastic is much lighter and more aerodynamic than metal, which improves the cars fuel effeciency. Plastic is also easier to shape, which is useful during both the manufacturing and bumper repair process.

Bumpers of most modern automobiles have been made of a combination of polycarbonate (PC) and acrylonitrie butadiene styrene (ABS) called PC/ ABS.

OBJECTIVE

To design Bumper as per automotive industry Standurd.
Create tooling axis for the given CLASS-A surface.
Create B Class and C Class surfaces.
Create final surface model and convert it into solid body using close surface command in the part design workbench.
Perform draft analysis for both Class-A surface and Final part body.

Design Methodology

Skin data would be provided to us by the styling team to us.
Class-A surfaces means visible surface. It gives the aezthetic of the component which is created by the styling team and gives to the part design engineer to create the part with all engineering aspects.

The first step is to check the continiuty of the class A surface. This is to ensure that there is no gap between surfaces. If we find any then we should fix that first. Class-A continuity check
Analyse the cass A surfaces through visual inspection.
To make sure that the given surfaces has no gap in between them. we can check it also with the help of join or boundary commands.

Procedure for creatingthe tooling axis

Tooling axis represents the opening and closing of the mold core and cavity during the manufacturing of the components. A plastic product designer should consider the best tooling direction to cutdown the cost of the component very less.

Method opted for creating tooling axis for the bumper

Check the best toolingg direction for the given surface.
We can find out the best tooling direction by cross checking all the three axes.
Here we can find out tha the best tooling direction for the bumpor Class A surface is along X-dirction
The method I choose to create the tooling axis is first extracted a surface and create a mid point on the on the surface. The introdused an axis system on the point.
Then created a with the point and directiin along X axis.
Here both the outer flanges have 5.1- degree with respect to the axis created. Hence going with the axis created will not make any difficulties during the draft analysis.

Another method is by creating intersection along direction. and then create lines on the walls and then create a bisecting line with the lnes on the wall and point created earlier we wil get an axis which will satisy the draft analysis requirement.

Draft analysis for the given class A surface

The Deaft Analysis is a 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 analysed eement where the deviation from the draft direction at any point, corresponds to specified values.

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

Procedure for performing the draft analysis are as follows.
Change the view mode of the component to be in customized parameter mode and then slect the shading mode as materials.
Then open the featured draft analysis tool from the insert menu.

Then click on use the compass to define the current drafting direction and then drag and align the compass on the tooling axis.
Then lock the draft direction and performed draft analysis by clicking on the component.
The green colour shows the positie draft tooling direction and the given surface passes the draft analysis.
Click on th analysis under the running point to check the draft analysis on the individual faces. It shows how much draft on specific points when we move the cursor point.

Surface B Creation

Class-B suface means thickness ofa pargt is not visible and is inside part. In the words Class-A surface. This is the surface that contains engineering aspects of a model.

Offset the class-A surface to 3mm inword direction.
Rework on the patches and discontuinity of the offset surfaces using the features like extract, multi-extract, sweep, multi section surfaces, extrapolate.
To ensure the continuity of the Class-B Surface check the boundary command to find out the boundary.
Hence Class-B surface creation is done.

Surface-C Creation

Surface that joins class-A and class-B surface Class-C surface. Class C is often specified for interior surfaces not readily visible, surfaces that will be covered by another part when assembled.

Since it is complex class-A surface, we cannnot simply create the class-A boundary curve and sweep it at one shot. hence, we need to to create smaller curves using multi-extract command and then create sweep of 90 degree with reference to the surface option, sweeps at the idportion of the bumper should have a 93 degree value to pass the draft analysis.