Week 9 - Project 1 - Door Trim Lower with Engineering Features
Objective: The main aim of this challenge is to create a solid body of 'Door Trim Lower' with the help of the closed surface method by using the 'Generative shape design' workbench in CATIA V5. Performing the 'Draft Analysis' on the solid part body of the Door trim.
Overview:
Initially, we need to offset the given Door Trim class A surface in the inner direction to the required thickness (here the thickness is 2.5mm). After that, we need to close the patches on the offset surface of the bumper, the patches are formed due to the fillets on the Class A surface. Once all the patches are closed properly join them together to make a proper class B surface and now sweep the boundary of the class A surface to trim with the class B surface to make a closed body. By using the closed body command in the Prat workbench we can get the solid body from the closed surface of the Door Trim. Now, I created the Heat stakes and Locators by considering all the design parameters. After creating all the B-side features on the solid part body of the door trim, I performed a draft analysis for it to check whether all the surfaces are drafted properly or not (The draft angle for the plastic component is 0.5deg to 3deg).
LOCATORS:
A round locating pin located concentrically in a hole is a common application of a 4-way pin, and helps to further secure the piece. 4-WAY LOCATORS: 4-way mean you prevent movement at 2 axes (+X, -X, +Y and -Y) on the plane. Generally, you have cylindrical pin on the fixture and circular hole at workpiece part.
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:
HEAT STAKES:
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.
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.
DOG HOUSE:
Dog house is an engineering feature used in plastic trim design. Dog houses are used as supporting feature. Sometimes other engineering features like snaps; locators etc. are mounded on them to increase their strength
CREATING THE DOGHOUSE
The dog house is an engineering feature used in the plastic trim design. Dog houses are used as a supporting feature. Sometimes other engineering features like snaps; locators, etc. are mounded on them to increase their strength.
The doghouse is created by following the design rules.
The nominal wall thickness guide range is from 0.75 mm to 3 mm for reinforced materials and 0.5 mm to 5 mm for unreinforced materials.
Related Courses
WALL THICKNESS (W) = 0.70 (NOMINAL THICKNESS OF PLASTIC MATERIAL)
This process is usually done by Thicken surface command.
An important thing while designing a doghouse is to maintain 40% less thickness than the wall thickness (T) at the area of the intersection to avoid sink marks. So, a C shape is formed at the intersection.
This can be made using the split command to remove the solid at the intersection
Draft Analysis
