Week 9 - Challenge 3 - Bumper

FRONT BUMPER

AIM:

To create the bumper plastic component through the given Class A Surface and to perform draft analysis on the plastic component.

OBJECTIVES:

· Create the Tooling Axis

· Create the Class B and C Surface

· Create the Close Surface

· Perform Draft Analysis

BUMPER:

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.

They are designed to absorb impact onto the front and rear of vehicles and minimize low-speed collision damage. Today, standard passenger's vehicle bumpers have a rigid reinforcing bar under the outer cover, with sections of compressible foam or plastic underneath.

Fig.1 Bumper

A bumper is made up of four parts:

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

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

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

Plastic 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 car's fuel efficiency. 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 acrylonitrile butadiene styrene (ABS) called PC/ABS.

CLASS A SURFACE:

It is the aesthetic surface and the outer surface. The Class A surface is given as input to the plastic designer to create the plastic component.

Import the Class A surface and check for gaps using boundary in the given class A surface. Then Create a tooling axis to check the given surface is capable for drafting.

Fig.2 Class A surface

TOOLING AXIS:

It is the direction in which the core and cavity opens and closes. After the class A is imported check for possible irregularity, using boundary.

Extract a flat surface, create a point on the flat surface using on surface option. Create a line using point direction in the point on surface. The created line is the tooling axis, perform draft analysis on the class A surface using tooling axis.

Fig.3 Tooling Axis

CLASS B SURFACE

The offset from Class A surface is used to produce the class B surface. Offset the given Class A surface inward to 3mm. There will be certain patches in the offset surface, close all the surfaces using multi-section surface.

Fig.4 Class B surface

CLASS C SURFACE:

This is the surface that connects the class A and B surfaces together. After joining surfaces together check the draft analysis on the final component, convert the component into a closed surface.

Using multiple extract, extract the surfaces on the boundary and extract the boundaries. split the boundaries and do sweep on them separately based on reference surface option.

Join all sweeps together and perform sweep separately on the inner boundaries. join all the sweeps with the class A surface.

Fig.5 Class C Surface

FINAL TRIM

Join the class A and C together and trim the join with the B surface. Trim the above joined surface with the Class B surface to get the final plastic component

Fig.6 Final Part

CLOSED SURFACE:

Import the final component on the part workbench, defines the part body and do close surface operation on the final trim.

Fig.7 Closed surface

DRAFT ANALYSIS

The Draft 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 element 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 check whether the minimum draft (3 degrees) is maintained or not.

Fig.8.1 draft analysis (Class A Surface)

Fig.8.2 draft analysis (closed surface)