Challenge

Week 9 - Project 1 - Door Trim Lower with Engineering Features

HHarikrishnan M S3 Aug 2022

AIM : Create the Door Trim Plastic component through the given Class-A surface.

TOOLING AXIS :

Tooling axis is the direction in which the core and cavity opens and closes. In order to construct the Class B and Class C surfaces, it is crucial to determine the tooling axis from a Class A surface since this axis serves as a reference line for the draft angle.

In this challenge, the tooling axis is discovered by just sketching a line perpendicular to the surface as shown below.

BISECTING METHOD :

It's a method of finding tooling axis. In order to find the tooling axis we need to under find the better tooling direction by analysing the body.
Finding tooling axis should be in a manner which will reduce the manufacturing cost, like wise there will be some better tooling direction which can avoid the use of side core.
If we get the better tooling direction as Z axis. Firstly find the tooling direction in X and Y axis if there are inclined surface to be considered this is achieved by intersection solid and bisecting method.
After finding both the tooling axis in X and Y direction, bisect it to find the main tooling axis.

DRAFT ANALYSIS :

In order to recognise that our drafted component is at an angle that is higher than the typical draft angle, which is about 3 degrees, draft analysis is employed. Draft analysis is done using a tool in Catia called "Feature draft analysis." When you click on this tool, the window below will appear.

In the mode section, there are two modes: the Quick analysis mode and the Full analysis mode. In this challenge, quick analysis mode is being used to visualise draft analysis.
First, a tool named "Compass" from the direction category is used to define new draft direction. The direction of the draft is determined by positioning that compass above the tooling axis.
Then by just clicking over the surface or the component we can visualize the colour corresponding to the angle as set in the draft analysis.
There is an another tool which is used to find angles at running points. The tool is under display category, in that by selecting the tool named "Analyses under the running point" there by moving the cursor over the component gives the draft angle at that particular point on the component.
There is an another tool to change the draft direction of the compass, which is under direction category next to the compass tool.

PROCEDURE :

Tooling axis is found as explained in the theory section.
By Feature draft analysis tool the draft analysis of the class A surface is done initially to know whether our find class A is acceptable or not. And the given class A is acceptable.

DRAFT ANALYSIS OF CLASS A

Then nextly creating class B surface just by offseting class A by 2.5 mm.
The class B will have some gaps on the surface and those gaps are cleared by multi sections surface command.
After solving those gaps in class B, class C surface is created, then trimmed the unneessary portions to get the exact bumper design.
By using close surface command in the part design the surface body is converted to part body.
Then the draft analysis of that particular part body is performed.

DRAFT ANALYSIS OF PART BODY

ENGINEERING FEATURES

HEAT STAKE :

It's an Engineering feature provided at the B surface of a component, which is laterly used to join this component with another component by Heat staking. Heat staking also known as thermoplastic staking is the process of joining two dissimilar materials together. In heat staking we use local heating and cooling to raise the temperature of plastic components and allow plastic reforming to be carried out. This reforming can be used in a wide variety of applications.

LOCATORS :

Locators are something which is used to fix the component during machining process. The components are having 12 degrees of freedom, so for to arrest these motions locators are used.

In our design I have provided two locators and 16 Heat stake at the B surface of the component.

DRAFT ANALYSIS OF HEAT STAKE

The draft angle is provided about 0.5 degrees even though it's highlighted in red that's because some of the area do not achieve 0.5 degrees w.r.t the tooling axis. But it will follow draft angle when the minimum draft angle is provided to 0.49 degrees as shown in the below image.

DRAFT ANALYSIS OF LOCATOR

Locators are also provided with the draft angle of 0.5 degrees and as mentioned earlier some of the areas do not achieve minimum draft angle w.r.t the tooling axis. When the minimum draft angle is changed to 0.49 degrees it's found in green which means the component is following draft angle of 0.49 degrees.