Week 9 - Project 1 - Door Applique Design with Engineering Features

Aim

• To Create the Door Applique Plastic component through the given Class-A surface.
• To create the tooling axis for the given Class-A Surface meeting the requirements of the draft angle.
• To perform the Draft analysis on the model.

Introduction

Car Door Applique

3-2-1 Principle

It is one of the most commonly used principle in design whenever the part is to be fixed condition.A part has 6 translational motion(positive and negative X,Y,Z) and 6 rotational motion(Clockwise and counter-clockwise in X,Y,Z) A completely fixed part has 0 degrees of freedom.

The two way locators or four way loactors can be used to restric the motions in required directions

Draft

Draft is the amount of taper for molded or cast parts perpendicular to the parting line. It also a slant that is applied to each side of most features of an injection molded part By applying appropriate draft angle the mold will be easier to remove and it also accounts for thermoplastic shrinkage in Injection molding. The draft may also alter the form and fit of the part during assembly.

A draft of minimum of 0.5 degree draft per side is recommended. For textured sidewalls use an additional 0.4 degree draft per 0.1mm depth of texture. But maintaning the minimum draft could be costly during manufacturing hence an optimum draft angle of 3 degree could be maintained.

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.Heat Staking eliminates the need for extra hardware, which can become defective, break, or otherwise suffer from quality control issues.

Materials Used:- Polycarbonate (PC), Polypropylene (PP), Polystyrene (PS), Acrylonitrile butadiene styrene (ABS), Nylon.

Advantages

• Heat staking is done in one machine cycle.
• Heat staking is safe to use with a broad range of electronics and produces a higher pull strength versus the ultrasonic technique.
• very less Mechanical Vibration

Applications

• Heat staking LED Stamped Arrays or LED Flex Circuits into the plastic housings for OEM automotive and aerospace industries.
• Heat staking is also the preferred process in many medical device assembly applications for attaching adhesive patches to wearable glucose monitor devices and wearable medicine dispense devices versus the more brittle feel of an ultrasonic welded patch against the patient’s skin.

Door Applique desgin

Types of surfaces involved

Class A surface

This is the input surface for the design engineers for designing the inner panels or features of the parts. It is the styling surface of the component which shows the outer appearance of the parts.

Class B surface

The thickened surface is called as B surface. It is also called as engineering surface. This surface contains all the necessary part feature like fillet, ribs, bosses etc.

Class C surface

The surface joining the class A surface and class B surface is called as C surface.

Steps involved in creating Door Applique desgin

Tree structure

Check the class A surface

• The input (class A surface) is checked for any gaps or disjoints using the join or boundary commands.
• If there is any Minor error the it can be rectified or else send back to the Class A surface designer to make the necessary modifications properly.

In this case we can see that the Class A surface does not have any gaps or disjoints and has smooth and continuous boundary.

Create the Tooling axis

The tooling axis is the direction in which the core and cavity opens and closes. In this case we can see that the Class A surface center point can be used as tooling axis center point in the Y direction.

Publish

In the next step publish the tooling axis and Class A,B,C surfaces so that we can access it easily and use it for further creation of surfaces or thick body.

Draft Analysis

Once the tooling axis is created the draft analysis can be done. For viewing the draft analysis results we need to change the view parameters into customise mode enabling only the material.

Go to insert-analysis-feature draft analysis.

The compass option is used to choose the tooling axis. The color coding shows the result of the draft analysis done. The limits of the draft angle can be changes according to the needs.

Types of the modes in the analysis

A single limt can be chosen to show the positive or negative draft

Multiple limits can also be set based on the requirements

The draft angle value can be found at any given point of the surface. For this case 0.5 egree is chosen as the optimum angle and we can see that the some parts of the model has positive draft angle highlighted in green color and some parts with zero draft highlighted in blue color. The negative draft is shown in red color.

Class A Surface Draft Analysis

Applique attachment surface draft analysis

Door applique draft analysis

Door applique

B surface Creation

The inner inclined portion of the class A surface is extracted and then offsetted to 2.5mm

The surface is extrapolated and trimmed to get the required surface

Class C Surface creation

The Class C surface is created by sweeping the Class a surface boundary along the tooling axis

The the class A and C surface are joined

Then the surfaces are trimmed off to get the required surface.

Then the close surface command is used to get the solid body

Part images

Top view

Front view

Side view

Isometric view

Conclusion

Thus the door applique with the attachment features has been created and the draft analysis was done.