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

AIM: Create the Door Trim 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.

THEORY

CLASS A SURFACE: Class A surface is a surface made by the designer specially in automotive design which is the aesthetic part of a body and is given as an input to the plastic designer to work on it.

CLASS B SURFACE: It is a surface which comes below the class A surface with a particular thickness. This surface contains engineering features of a model.

CLASS C SURFACE: It is the surface which joins class A with class b surface.

TOOLING AXIS: Tooling axis is the direction in which the core and cavity opens. If we are using proper tooling axis, we can avoid adding side cores thus the cost of manufacturing the component can be reduced.

It is defined as the direction in which the mould/core and cavity open. Selection of the direction of the tooling axis depends on the ease at which components can be easily ejected.

Generally tooling axis is decided from the natural axis of the design, that is, tooling axis is analysed with the x, y and z axis of the system. If the axis doesn’t clear the draft analysis, the next step is to look for the surface in which the drafting axis can be created in such a way that the axis is normal to the surface taken. These are the methods of deciding tooling axis. Bisecting method is the least used method.

DRAFT ANALYSIS: From draft analysis, we can verify draft angles, examine the angle changes within a face, as well as locate parting lines, injection and ejection surfaces in parts.

It is an important feature in Catia which helps the user to analyse the draft on various surfaces. The draft analysis toolbar provides two modes for analysis of the draft, first is the quick analysis which basically has three colours (green, red, and blue) for analysing on the other hand other option is the full analysis mode which enables a few more details into the draft and is used in the complex components.

Draft analysis in Catia:

Step 1: Ensure that customize view parameter is enabled and material mode is opted in view mode customization.

Step 2: Now go to insert > analysis > feature draft analysis.

PROCEDURE

Creation Of Class A Surface

• Class A surface is obtained as the input.
• Join all the surfaces to obtain Class A surface if different surfaces are given as input and ensure no gap is present between any surfaces. Thus, Class A surface is obtained and publish it. Here, the provided surface is completely joined and can be taken as class A surface.
• For the file provided, there is a projection which is found out to be not the part of real class A surface, so that surface is splitted from main class A surface.
• Publish class A surface.

Creation Of Tooling Axis

• i am selecting a plane surface and take a point surface on midle and create a line on pont.

Draft Analysis Of Class A surface

• Draft analysis is performed over Class A surface and every surface is obtained as clearing.

Surfaces obtained are all green in color, which means that the surfaces are clearing the draft analysis.

Creation Of Class B Surface

• Now, Class B surface has to be created. For this, multiple extract is used to extract surface in a single operation. Surfaces obtained are the offsetted for 2.5mm.
• Small filleted portions are avoided from extract and other surfaces are extracted. Small fillets are avoided as when they are offsetted to 2.5mm, fillets cannot be automatically formed in CATIA.
• Similarly, other surfaces are extracted avoiding the fillets and offsetted, extrapolated and trimmed with the main surface to get proper B class surface.
• Fillets are measured from the Class A surfaces and appropriate fillets are provided for Class B surface by adding or subtracting the thickness of the component to obtain correct thickness everywhere.
• Publish class B surface.

we taking offset 2.5mm and we got some error.

we are use two method to fix this part but all method are error.

1.offset mehod

2.Multisection method:

LASTLY WE USE FILL METHOD . I know this method is no recomended but i have no option.

Creation Of Class C Surface

• Now class C surface has to be created and it is created from the boundaries obtained from the Class A surface. This boundary is provided as the input curve for sweep command. Using sweep command, class C surface is created.
• Appropriate sweep is the provided considering the flash and considering manufacturing procedures. Surfaces are extrapolated if necessary.
• Publish class C surface.

Creation Of Closed Surface

• Now Class A surface and Class C surface is joined.

Boundary check is done to check for any open boundaries in the part.

The closed surface then obtained moved to part design and close surface tool is used to obtain the part.

Screenshots Of The Solid Model With The Proper Color Code Of The Draft Angle In Various Orientations

CREATION OF LOCATORS:

To create the locators, I created a sketch on the body. After creating the sketch, I pad it 20mm in height and thicken it to 1.3mm and I drafted it with 0.5deg in the direction of the tooling axis. I gave 5mm of chamfer with 45deg of inclination and after I gave a fillet of 0.25mm radius.

4-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 12mm in height and 1mm in thickness. After padding the ribs, I drafted 0.5deg in the tooling asix 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 with supporting ribs:

Now I Power copy the heat stakes by giving inputs like point and plane copy them in the part body according to the requirement.

Final part body with 4-way locators including all the heat stakes with supporting ribs:

CREATION OF RIBS:

Ribs are a feature in plastic injection molded parts. They are thin extensions that run perpendicular from a wall or plane. They are commonly used to provide additional support and strength to a part. Thickness and location are essential to rib design.

To create the ribs, I draw a sketch and padded it to 12mm in height and 1mm in thickness. After padding the ribs, I drafted 0.5deg in the tooling asix direction and filleted it with a 0.25mm radius.

use power copy to produce rib and another two ribs are produce using tranlate command to have command on both the steps.

Tree structure: