Challenge

Week 10 - Challenge 3 - Door Trim Lower with Engineering Features

VV.Balasekar V11 Jul 2023

Aim

Create the Door Trim Lower 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 the draft angle and at the end perform the Draft analysis on the model.

Create the Heat Stakes and the locators considering the design rules mentioned in the video for the door applique.

DESIGN METHODOLOGY

Skin data would be provided to us by the styling team.
Class-A surface means visible surface. It gives the aesthetic 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 continuity 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 class A surface through visual inspection.
To make sure that the given surface has no gap in between them. We can check it also with the help of Join or boundary commands.

Procedure for creating the 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 door handle

Check the best tooling 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 that the best tooling direction for the pumper class-A surface is along Y-axis direction.

Creating tooling axis

We should create a Dummy tooling axis first by creating point and line.

Select the curve in existing class A surface and create a dummy tooling axis for reference.Highlighted pink colour is tooling axis.

Draft analysis for the given CLASS-A surface

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.

Procedure for performing the draft analysis are as follows
Change the view mode of the component to be in customized parameter mode and then select 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 without activation the compass and then activate the compass in the dialogue box drag and align the compass on the Tooling axis.

Then lock the draft direction and perform draft analysis by clicking on the component
The green colour shows the positive daft tooling direction and the given surface passes the draft analysis.
Click on the 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 surface means thickness of a part it is not visible and is inside part. In other words, Class-B surface is a surface below a certain thickness from the class-A surface. This is the surface that contains engineering aspects of a model.

Offset the class-A surface to 2.5mm inward direction.
After offset ,There will be some open patches in the fillet area ,Found an open patches as shown in below images.

Procedure for rework on the patches and discontinuity of the offset surfaces using the features like Boundary, extract, multi-extract, join,extrapolate,Trim and edge fillet.

First remove the patches fillets by join - sub elements to remove command

Extract the base and vertical wall surfaces by multiple extract command

Extraplotate the surface to make two surface extend and to make trim

After trim

The highlighted surface will through error while final trim of A-C & B.So to make the surface even,created plane and splited the extra portion.

Applying fillet radius

To find the radius ,the radius surface has been extracted and untrimmed from the class A surface and thus radius value is obtained by measuring tools.

Finally, the required corners have been filleted by even wall thickness to avoid the mould flow marks.

Final B_Surface

To ensure the continuity of the Class-B surfaces check the boundary command to find out the boundary.
Hence class-B surface creation is done.

Creation of C Surface

Surface that joins class-A and class-B surfaces is 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 a complex class-A surface with several sharp corneres, we cannot simply create the class-A boundary curve and sweep it at one shot.
Hence, we need to create smaller boundary and then create sweep,Multi section surface.
If the surface is perpendicular to the tooling axis we have to provide 3 degree draft with reference to the tooling direction.
Use Multi surface command to close the gap between the two elements.

Final C Surface

Creating the final surface of Door Trim

First step is to join the CLASS-A surface with CLASS-C surface.

Final A-C join

FInal A-C&B trim

Go to the part design work bench and using the close surface command create the door handle solid part body

PROCEDURE TO ADD ENGINEERING FEATURES:

1. LOCATORS

2. HEAT STAKES WITH GUSSETS

USE OF LOCATORS: Any workpiece has 12 degrees of freedom for movement in space that consists of 6 Axial and 6 Radial Degrees of Freedom. All 12 degrees of freedom must be restricted to ensure proper referencing of a workpiece. These 6 Axial Degrees of Freedom permit Straight-Line Movement in both directions along the 3-principle axis shown as X, Y & Z. The Radial Degrees of Freedom permit Rotational Movement, in both Clockwise & Counterclockwise radial directions around the same three axes.

We have two objectives when assembling the child component with the parent component:
1. Accurately position the part at the desired coordinates.
2. Restrict all degrees of freedom except the one direction in which it'll fix so that the part

PROCEDURE TO CREATE THE LOCATORS:

SKETCH FOR THE LOCATOR:

To create the locators, I created a sketch on the body. After creating the sketch, I pad it 22mm in height and thicken it to 1.3mm and I drafted it with 0.5deg in the direction of the tooling axis. I gave 3mm of chamfer with 45deg of inclination and after I gave a fillet of 0.3mm radius.

4-way locator:

4 Way locator

2 Way locator

CREATION OF HEAT STAKES:

To create the heat stakes, I draw a sketch on the surface. After the creation of the sketch, I pad it to 18mm height and I gave a draft angle of 0.5deg on both sides (inside and outside) and then I gave a fillet with a 0.25mm radius. After creating the heat stake, I created the ribs for supporting purposes. To create the ribs, I draw a sketch and padded it to 6mm in height and 1mm in thickness. After padding the ribs, I drafted 0.5deg in the tooling axis direction and filleted it with a 0.25mm radius. Finally, I union trim the ribs with a heat stake to remove the ribs, which are present inside the heat stakes.

Heat stake sketch:

Now I translated the heat stakes by copy-paste special them in the part body according to the requirement.
Final part body with 4-way and 2-way locators including all the heat stakes with supporting ribs: