Week 9 - Project - A pillar Design with Master Section

OBJECTIVES:

• To create the class B and class C surfaces from the given class A surface.
• To form a solid geometry by combining all the surfaces.
• To create a dog house for the solid part whilst following the design rules.
• To perform draft analysis on the class A surface and the solid part model.

The structure of an automobile body consists of various support structures like the roof, pillars, and floor. The car pillar in the vehicle stands in the near-vertical position, which supports the vehicle’s roof. The pillars found most commonly are the A, B, C and D pillars.

The A pillars are the first set of upright sections on a car body that links the lower body to the roof of the car. It acts as a major support structure during impacts and it is also a median to support the windshield of the vehicle. Apart from structural advantages the A pillar has a large effect on the overall aerodynamics of the vehicle.

GIVEN SURFACE-A:

A-Pillar Step File

TOOLING AXIS:

• The next step is to create the tooling axis for the part which will determine the direction in which the core and cavity of the mould will move.
• Designer must ensure that all holes and slots are covered in the main tooling and thus side core must be avoided whenever possible
  After analysing visually for the best possible tooling axis, an reference tooling axis is created on the centre of one of the surfaces of the A pillar trim.
• The main tooling axis is created by using the bisecting method and by taking references from the master section.

DRAFT ANALYSIS:

• Draft analysis is done on the class a surface after the tooling axis has been obtained.
• The part must have a minimum draft angle of 3 degrees on all the tapered faces.
• Using the feature draft analysis tool and the compass the part surface is validated for the minimum draft criteria.

CLASS B SURFACE:

• After all the validation has been done, the class B surface is created by offsetting the class B surface to a distance of 2.5 mm.
• After offsetting a large opening in the surfaces is found which is closed with the help of sweep and multi section commands.
• The class B surface is then extrapolated in parts to trim it along with the class C surface.

CLASS C SURFACE:

• The class C surface which connects the class A and class B surface is created by sweeping the boundary of the class A and using the class A as a reference.
• The sweep is divided into several parts in order to avoid complexity
• Surfaces which are parallel to the tooling direction are swept with the tooling axis as reference and with a draft angle of 3degrees.

DESIGN OF DOG HOUSE:

• The two main purposes of a dog house are to avoid sink marks and to house various other engineering features like screw boss, locators etc.
• The dog house should follow certain design rules which are stated below.