Week 11 - Final project
AIM: To design and develop vehicle interior door trim using Catia V5 with given class A surface and Master section. Also, create the Side Attachment features as per design rules.
OBJECTIVE:
- To create thickened part using the master section for reference
- To create the mounting features as per design guidelines in the industry and with master sections
- To perform Draft analysis & Tooling analysis
DOOR TRIM :
The door panel is the interface between the car's interior and the door's inner workings Generally the door panel is divided into parts for easy design like an armrest map pocket, land, and lower substrate. This requires one of the toughest requirements among the interior parts of the car. This should be designed to withstand the load while being less than 2.5mm in thickness and also to protect the occupants during collisions.
The door currently has an inner full-width panel consisting of electronic windows, ca central locking system, and speakers. These panels typically consist of a foamed core covered with either textiles or plastics.
PROCEDURE:
Creating the Tooling Axis:
TOOLING AXIS:
There are three types of tooling axis :
- with respect to the axis (X, Y, Z)
- normal to the surface
- bisecting surface
The tooling direction is used to find the direction in which the part is removed from the core and cavity. The draft angle should be positive to the tooling axis to manufacture the component easily.
Step: 1
Creating the tooling axis for Map Pocket with bottle holder by create a point on surfaces respectively to the 0 value. It automatically creates at the mid surface and generates the line to the direction of the y-axis.
Step: 2
Creating the tooling axis for Map Pocket by create a point on surfaces respectively to the 0 value. It automatically creates a mid surface and generates the line to the direction of the y-axis.
Step: 3
Creating the tooling axis for Lower Substrate by create a point on surfaces respectively to the 0 value.
Step: 4
Creating the tooling axis for Arm Rest by create a point on surfaces respectively .
Creating the sliding tooling axis for the arm rest by extracting the side walls of the surface. Creating the point on the surface with the axis system, here y axis is considered as removal direction, hence line is created to the y-axis as shown below.
Class B Surface:
It is the offset of the class A surface at a particular distance. The offset distance depends on the thickness between Class A and Class B surface. In Class B Surface, where the attachment features are built in and attached.
Here, the thickness given is = 2.5mm.
Procedures to build class B surface:
- Offsetted the joined surfaces from class A to 2.5mm inorder to create class B surface.
- Extrapolated the offseted surfaces inorder to make sure all the surfaces are in contact.
- Trimmed the offsets to get an output same as class A surface
- Fillets are given to the required edges based on the thickness and curvature of the class A fillets.
Finally we achieved the B class surface by extracting and offset the Class A surfaces.
Creation of C Surfaces:
Class C Surface:
This surface connects the Class A and Class B surfaces. (Surface in between Class A & B surfaces)
Procedure to build Class C surface:
- Boundary of class A surface is extracted and then smoothcurved the boundaries if it's required
- Also if needed Multi-Section Surface command can be used to create the Class C Surface
- Then that boundary is swept along with respect to Tooling Axis until it gets coincided with the offsetted class B surface.
- Or else the boundary is swept perpendicular to the Class A Surface until it gets coincided with the offseted class B surface.
- Both the sweep surface and multi-section surface are joined together to form as a single one.
A&C JOIN :
Once the all surface joined together it extrapolated to certain distance to trim with A Class surface to C surface. Finally, we created a Class C surface.
Creating the Heat Stake:
Heat staking is a pulsed – heat process to join two or more parts out of which one at least is made of plastic . The plastic is to deform the plastic material using the heat and foam at a set process time. The bond is made by partially de forming the plastic part in order to fix the other. Heat stakes makes it easily to bond metal to plastic is commonly used in high volume and low-cost application such as Automotive, IT, and consumer appliances.
Step: 1
Creating the sketch by extracting the class A surface, by each surfaces separately, point and axis system created simultaneously on the surface. Using positioned sketch.
Step: 2
The sketch feature is then extracted to the required dimension. And it is drafted for the 0.5 deg to the sliding tooling axis, it is filleted for a radius 0.5mm of smooth edges as shown below
The support rib as created, where the flange will come and sits to get arrested to the heat stake.
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. Dog houses are subjected to draft analysis to prevent breakage of the component during ejection from mould cavity. Dog house and other engineering components are built on B-surface. In this we remaster the dog house and union trim with the main solid part of the plastics.
CORING:
coring is given to avoid the shirnk mark in while doing the injection molding . as per the dog house guidelines i given the coring dimention .
Making the Final plastic Component:
To make the final component the Class C surface is trimmed with Class B surface, the output will get the component with a 2.5 mm thickness of surface and it is converted into a solid body using the insert body option in part design as shown below.
Performing Draft Analysis:
The Draft Analysis command enables you to detect if the part you drafted will be easily removed. This type of analysis is performed based on color ranges identifying zones on the analyzed component where the deviation from the draft direction at any point, corresponds to specified values. This rule of thumb applies to parts with mold depths of up to 2 inches. At this size, draft as low as 1½ degrees will allow for an easy, non-damaging release from the mold when the expected shrinkage of the thermoplastic material occurs.
It’s also important to remember that draft angles are just one component of an effectively designed injection molded piece. Design for manufacture is one of the easiest ways to improve the quality and efficiency of your injection molding process, and it never hurts to stay up to speed on all injection molding best practices.
Draft analysis on Door Trim Solid Body with attachment features:
Step: 1
First we have to set the compass on the main tooling axis to get the direction of core and part moves along as shown below.
Here the draft angle is given as 3 degree. Hence we achieved green colour on top surface. Hence it accepts the draft angle for the surface, so we build good quality component.
Now we check colour variant scale to ensure the maximum and minimum area draft angle is achieved by displaying by green, red and blue colour respectively. If the surface appears red in colour while analysing it is not accepted.
We can check the angle of draft given to surface by using draft tool analysis just point the over the surface where we have check angle of given draft to the component as shown below.
Step: 2
A sliding axis for the Arm rest component has been done separately by using sliding tooling axis as shown below.
Step: 3
For Attachment Features the draft angle is applied for 0.5 deg and its analyzed using the sliding tooling axis as shown below.
Screenshot view of Door Trim Component :
Creation of the car interior door trim is designed using the given class A surface as the input and Class B and C surface created with the help of Class A surface. By using the given master section attachment features I.e. Heat stakes, Flanges, Dog House are created using the design rules. The draft analysis has been performed to analysis the draft of the component to manufacture easily applying draft to the surface by 3 degree and 0.5 degree to the attachment features. With all data and report we can conclude that draft analysis is very important to design any plastic component to mold the plastic easily. The analysis will verify that all surfaces are favorable for being pulled from a cavity. It may also highlight or given insight to defect areas.