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

AIM : design of door trim with engineering features. 

ENGINEERING FEATURES : 

• HEAT STAKE :

Heat staking also known as thermoplastic staking is the process of joining two dissimilar materials together. In this method, local heating is done in the heatstake region to make the plastic meltand flow over the other plastic component and cools for some time to get solidified.

Applications range from staking plastic bosses for assembly of car door panels to joining PCB’s to plastic housings. Benefits of this technique include; no vibration damage, no particulates, the ability to stake metalized coated applications and the capability to stake in difficult to access or restricted areas.

HEAT STAKE IN AUTOMOTIVE DOOR PANEL : 

• LOCATORS : 

Locators provide a positive stop for the workpiece. Placed against the stop, the workpiece cannot move. Clamps, on the other hand, rely only upon friction between the clamp and the clamped surface to hold the workpiece. Sufficient force could move the workpiece.

Generally, you have cylindrical pin on the fixture and circular hole at workpiece part.

TYPES OF LOCATOR : 

4 WAY LOCATOR :

It is used to arrest the 4 degrees of freedom and most commons used locator in automotive industry.

2 WAY LOCATOR : 

 A 2-way locating pin restricts motion along 1 axis (or 2 degrees of Freedom), It shape tends to like a round pin in a slot.

TREE STRUCTURE : 

TOOLING AXIS :

the tooling axis is created by point of (0,0) co- ordinates in the Class A surface and extend line is created along the point. this method is also used to clear the draft in all the direction . when ever there is a dent in a class A surface we can use this simple method for clearing the draft.

DRAFT ANALYSIS OF CLASS A SURFACE : 

GENERAL DESIGN CONSIDERATION : 

FOR BOSSES OR HEAT STAKE : 

• Draft  - 0.5 degrees on the walls of boss
•   Thickness -  Typically 40%* of the nominal wall at the base.
•   Height to Diameter Ratio -  3:1
•   Radii - 0.25mm maximum radii.  

FOR RIB : 

• Rib thickness w = 0.4*t
• Rib height =<5t
• Rib fillet radius - o.25 maximum
• Rib root thickness = 30% * t
• Rib thickness at the tip => 0.75 mm

FOR DOG HOUSE : 

• Doghouse wall thickness at the intersection of the part wall ( C ) should be 40% or less than the main wall stock ( T ). 

• The height of  ( B ) should be between 3.0 – 6.0 mm

DRAFT ANALYSIS OF THE FINAL COMPONENT : 

ISOMETRIC VIEW : 

FRONT VIEW : 

BOTTOM VIEW : 

SIDE VIEW :