Week 11 - Project - A pillar Design with Master Section

A-PILLAR DESIGN WITH MASTER SECTION

AIM:

To create the A Pillar Design with the master section given as the intersection sketch with the Class A surface and create the tooling axis and perform the Draft analysis for the final solid part.

Master Section

• Master sections are the guides for design requirements that decide the component packaging after technical (Styling, Concept, or Class-A) surfaces. Creating this master section should need 5 to 6 years of experience.
• This helps you to decide the feasibility, clearance, packaging, and fixation strategy before working it on a 3D. We have a master section.

• TOOLING AXIS

  In injection molding, the Class A surface is first analyzed to determine the axis or tooling direction that separates the molds. Tooling direction is critical for plastic product design because it determines mold direction.

  TOOLING AXIS CREATION

  • Tooling axis here created is by selecting one of the natural axes as it clears the draft.
  • Here, tooling axis is created by extracting one of the surfaces for creating a point and a new axis is created at that point.
  • So, a flat face is extracted and created a point at its centre. Axis is also created at that point.
  • Now, line is created using line tool and giving line type as point-direction and selected the point and direction for creating tooling axis and tooling axis is created along x direction.

• Draft Analysis

  To reduce the risk of damage to parts and tool while ejecting from mold a draft angle is provided to walls which are parallel to the tooling direction. It assists with releasing the part from mold.

  To perform Draft analysis in Catia, Draft analysis feature is used. For that First tooling Direction decided. Then make sure material view mode is used. After opening the window, align the compass with the tooling axis by dragging it on the axis. Then click on the surface or the body on which draft analysis is need to perform. In the bottom black colour window provide the minimum draft angle and then match the body color with this color scale. Green indicated draft angle is more than minimum draft angle. If it is blue then it is between 0 to minimum draft angle. And red denotes it is less than zero. By this way we can identify the areas with draft angle less than minimum draft angle and work on that area by changing tooling axis angle.

Creation of Class B and Class C Surface

Class B

• To create the class B surface, offset the class A surface inside as per our thickness requirement (here the thickness is 3mm, so I offset the class A to 3mm inside).
• Once the offset is created, we can observe some patches on the offset surface by taking the boundary for the offset surface, those patches are formed due to the fillets on the class A surface.
• We covered the patches by using the different surface commands (multi sections surface, fill, blend) in the Generative Shape Design workbench.

Class C

To create the class C surface concerning the boundary of the class A surface, I used the sweep command. Initially, I extracted the boundary of the class A surface with tangent continuity, and I sweep the extracted boundary concerning the surface at 90deg (for draft angle) for 4mm to intersect properly with the class B surface.Once we sweep all the surface boundaries of class A, extrapolate the swept surfaces until both surfaces got intersected properly, and trim them to remove extended extrapolated surfaces to get a proper sweep boundary throughout the entire surface, including the centre hole of the bumper. Now, join both class A and sweep boundary to get the complete class C surface. Now Class A surface and Class C surface is joined.Now Class B surface is also trimmed with the obtained surface to get the closed surface.Boundary check is done to check for any open boundaries in the part. The closed surface then obtained moved to part design and close surface tool is used to obtain the part.

Closed Surface

Creation of dog house

• Doghouses are created by following the design rules. For this, the sketch is created from the master section provided. It is then made into a closed body and is made into a part model.
• Shell operation is performed to get a hollow structure and then coring is done in order to avoid sink marks on the class A surface. Drafts are given for the surfaces as per design rules and proper fillets are also provided. As per the given master section, ribs and supporting features are also added to the doghouse.
• Then, the doghouse is added to the main body. All the sketches used are iso-constraint.

Final Draft analysis

Use the Featured Draft Analysis tool in the tools to now analyse the draft. After locating the compass and aligning it with the tooling axis, click on the lock symbol after aligning, and then click again on the surface after opening the draft analysis tool box.

Do this for both the axis and analyze A B C surfaces and Dog House.

FOR A SURFACE:

DOG HOUSE Draft analysis