Week 11 - Final project

AIM: To create AUTOMOTIVE DOOR TRIM Panel with the Engineering Features.

OBJECTIVE:The objective is to create a Door Trim from a Master Section along with the B- SIDE FEATURES following design rules.

INTRODUCTION:

It is an interior plastic part having engineering features that will locate or seats on the exterior sheet metal door pane.we have class A surface of door trim panel,which includes map pocket,lower substrate,bottle holder and armrest.

TOOLING AXIS CREATION:

• Master Section is first analysed for creation of tooling axis which tells about the direction of the mould or core and cavity slides.The tooling axis plays a vital role in the plastic design as there should be clearance between the tooling axis and mould.
• The minimum of 3 degree draft angle is provided on the surfaces which are 90 degrees to avoid the Interference between the mould and Injection moulding machine.
• The first step is to check whether the given class A surface has continuity or not.
• The next step is to check the possibilities of the tooling axis along x,y and z direction(NOTE : The surfaces must have clearance with the tooling axis and features such as holes must be cleared in the main tooling axis itself to avoid sidecore.)
• The Tooling clearance along x and Y are created and by using the bisecting line and tooling axis along x,y we will draw a TOOLING AXIS in which features like Hole and the inclined surfaces don't interfere with tooling axis.
• The Tooling axis should be published along with changing the graphic properties of the Tooling axis for ease of recognition.
• Here there is no opposite face in the y direction so we have drawn a line and given a minimum of 3 degree draft,but later due to draft analysis we changed that to 6 degrees.

DRAFT ANALYSIS:

• Draft angle is nothing but the amount of the taper is provided on the core and cavity for ease ejection of the mould after cooling.
• After Injection moulding the plastic parts shrinks and gets stuck to the core and it will make it difficult to remove the plastic part.
• If no draft or taper is provided on the core and cavity the inner layers of the platic part will undergo wear and tear and there will be NO smooth surface finish.
• The draft angle is provided on both the inner and outer walls of the core and cavity.
• The Nominal draft angle is 3 degrees
• The 5 degree draft can be given by the manufacturing cost will be more.
• The 7 degree draft is given for the textured surface.

STEPS FOLLOWED FOR THE DRAFT ANALYSIS:

• The part created has to be changed to the material mode.
• compass is enabled and aligned to the tooling axis.
• Lock command is used to lock the position of the compass.
• colour codes are classified and draft angle is analysed.
• Running point analysis is used to display draft angle at a specific position.

PLASTIC DEFECTS:

1.Flow Lines

2.Sink

3.Weld Lines

4.Vacuum Voids.

5.Shorts Shot

6.Burn Marks

7.Flash.

The above are the major defects in the plastic manufacturing in most of the cases it can be avoided in the product design stage itself.The flow lines,sink marks occur due to the varying thickness which can be controlled within the design stage.

The vacuum voids occur,burn marks occur due to the high temperatures of the molten plastic and low viscosity of molten plastic.

The Excess molten plastic is escaped from the parting surface and it will be removed with the help of knife or shaped objects. As a product designer we need to take care to make the parting surface should be on the B surface.

RIBS:

Ribs are used as an economical stiffness or strength in the plastic components without increasing the thickness.

Ribs facilitates as :

1.They can be used for locating and arresting purposes.

2.Providing alignment for the mating purpose.

3.Acting stops or guiding mechanisms.

DESIGN RULES FOR RIBS:

The major factors to remember while making Ribs are:

1.Thickness

2.spacing

3.Rib Height

4.Radius.

5.Draft Angle.

6.Location

Some standard dimensions for designing Ribs:

1.The Rib Height or depth can be maximum of 5x of component thickness.

2.Draft angle should be 0.5 degree minimum value

3.The radius value for the fillet should be 0.25 mm.

4.We can use two individual ribs in place of one long rib , the spacing between the two ribs should be 2t.

Here ‘t ‘represents the Thickness of the components.

The above standards are used for the ribs features faced inside the surface that customers will see.

3-2-1 PRINCIPLE:

If we need to constrain any object ,the object should be constrained in 12 degrees of freedom or 3 Translational motions along x,y and z and 3 Rotational motions along x,y and z.

Here we used a 4 way locator on one dog house and a two way locator on another dog house.

The locator works on the above 3-2-1 principle and main aim is to constraint the plastic body on the sheet metal body.

DOG HOUSE:

The main purpose for using the Dog House is:

The Dog House will avoid the formation of sink marks on the class A surface.

The screw boss can be placed on the dog house when required of more height.

Dog House wall thickness at the intersection of the part wall © should be 40% or less than the main wall stock (T).

Height of (B) should be between 3 to 6mm.

PUSH PINS:

Push pins also known as the dart type fasteners are versatile in design .

When light retention is required plastic push pins can be used as hole plugs.

CLASS A SURFACES:

MAP POCKET:

LOWER SUBSTRATE:

BOTTLE HOLDER:

ARM REST:

TOOLING AXIS ON MAP POCKET:

LIFTER AXIS FOR MAP POCKET:

MAP POCKET CLASS A DRAFT ANALYSIS:

TOOLING AXIS ON LOWER SUBTRATE:

LOWER SUBSTRATE CLASS A DRAFT ANALYSIS:

TOOLING AXIS ON BOTTLE HOLDER:

MAIN TOOLING AXIS:

LIFTER TOOLING AXIS:

BOTTLE HOLDER CLASS A DRAFT ANALYSIS:

TOOLING AXIS FOR ARM REST:

DRAFT ANALYSIS ON ARM REST:

CLASS B SURFACES:

• Create class B surface from the class A surface.
• Class B surface will be at a distance of 2.5mm
• To create class B surface extract the boundary of class A surface.

MAP POCKET:

LOWER SUBSTRATE:

BOTTLE HOLDER:

ARM REST:

CLASS C SURFACE:

• To join the class A and class B we need class C surface.
• Extract the boundary of the class A surface.
• Use sweep command with a minimum draft angle of 3 degrees along tooling axis.
• Join class A and class C surface.
• The excess part of c surface will be trimmed by using B surface.

MAP POCKET:

LOWER SUBSTRATE:

BOTTLE HOLDER:

ARM REST:

SOLID BODY:

• Join the class A and Class B surface and trim it with the class B surface to get close surface.
• Then go to part workbench and thicken the surface.

MAP POCKET:

LOWER SUBSTRATE:

BOTTLE HOLDER:

ARM REST:

DOG HOUSE:

RIBS:

HEAT STAKES & RIBS:

SUPPORTING RIBS:

PUSH PINS:

DRAFT ANALYSIS ON THE SOLID BODY:

MAP POCKET:

LOWER SUBSTRATE:

BOTTLE HOLDER:

ARM REST:

FINAL DOOR TRIM :