Week 11 - Final project

Aim:

To create a complete solid body of the inner door panel from the provided Class A surfraces. Lower substrate, Door armrest, Map pocket and Bottle Holder are the Class A surfaces given to us and these are the parts that requires to be convertred into solid bodies and assemble them along with the attachment features.

Role of a plastic in automobile industry:

The use of polymers as plastics in the construction of automobiles has continued to grow over the last decades. Nowadays they are the second most commonly found material in cars.

Here are four reasons why plastic is used in car manufacturing:

• Plastics reduce the weight of cars
• Plastics and polymers contribute to the safety of cars
• Plastics help to lower car manufacturing costs
• Polymers advance the design of vehicles

Some of the plastics used in a Car along with area where it is used is shown below:

Plastic parts are all individually designed and manufactured by a method called injection moulding and then later using attachment features they are all assembled together to make it a functionable component.

Injection moulding:

Injection moulding is a manufacturing process that allows for parts to be produced in large volumes. It works by injecting molten materials into a mould (or ‘mold’ in the United States). It is typically used as a mass production process to manufacture thousands of identical items. Injection moulding materials include metals, glasses, elastomers and confections, although it is most commonly used with thermoplastic and thermosetting polymers.

The first stage of injection moulding is to create the mould itself. Most moulds are made from metal, usually aluminium or steel, and precision machined to match the features of the product they are to produce.

Once the mould has been created by the mould-maker, the material for the part is fed into a heated barrel and mixed using a helical shaped screw. Heating bands melt the material in the barrel and the molten metal or molten plastic material is then fed into the mould cavity where it cools and hardens, matching the shape of the mould. The cooling time can be reduced through the use of cooling lines that circulate water or oil from an external temperature controller. Mould tools are mounted on plate moulds (or ‘platens’), which open once the material has solidified so that ejector pins can eject the part from the mould.Separate materials can be combined in one part in a type of injection moulding called a two-shot mould. This technique can be used to add a soft touch to plastic products, add colours to a part or produce items with different performance characteristics.

Moulds can be made of single or multiple cavities. Multiple cavity moulds can have identical parts in each cavity or can be unique to create parts of different geometries. Aluminium moulds are not best suited to high volume production or parts with narrow dimensional tolerances since they have inferior mechanical properties and can be prone to wear, deformation and damage due to the injection and clamping forces. While steel moulds are more durable they are also more expensive than aluminium moulds.

The injection moulding process requires careful design, including the shape and features of the part, the materials for the part and the mould and the properties of the moulding machine. As a result, there are various considerations that need to be taken into account when injection moulding.

Tooling Direction for Plastic Part

Tooling direction is main consideration for plastic part and mold parts because it defines movement of mold part and possibility of plastic part to come-out from mold part (Core and Cavity).

Tooling Direction:-

 

Now let us look into the Design procedures for the Assembly of Inner Door panel:

 

The Class A surface is received from the styling team. Then each part is separated into different parts and then using product workbench in CatiaV5 all the parts are clustered into one product.And then tooling axis for each part is created which is first and foremost thing before designing into a solid body and then B surface and C surface is created using the Class A surface and finally made into a solid body/ closed body with attachements features added wherever necessary for different parts to attach together.And finally Draft analysis is carried on the Solid Parts separately.

 

Attachement features are nothing but the flanges , heat stakes, doghouse with locators or screw boss or push pin these are all the features created on the B side features as it is the inner surface of the part. 

 

The above shown picture clearly shows the flanges along with the Heat stakes and Locators.

The above shown picture shows the doghouse with push pins on top of it for the attaching it inot the other side which in this case is attaching the inner door panel into the outer door panel.

 

Creation of Tooling axis on the given parts:

Tooling axis is very important before designing a part as it is this axis thorugh which the tool moves , so inorder to get even and clean injection of raw plastic into the mould the tooling axis should first be decided and draft analysis should be performed on this same tooling axis to get an idea about the possibility of tooling the design.

 

The below shown images are the A surface of parts with tooling axis.

 

Door arm rest tooling axis:

 

 

Lower substrate tooling axis:

 

 

Map pocket tooling axis:

 

 

Bottle Holder tooling axis:

 

 

 

Creation of B-surface and C surface and Close Surface:

 

After we created the tooling axis now we have to create the B surface and C surface of each parts and make it into a solid body.

For this purpose the A surface are extracted and according to the thickness specified the extracted surface is offset and then the C surface is created and finally they are all trimmed to make it into a single closed surface and then the closed surface is created into a Solid part.

 

Door arm rest:

 

 

Main substrate:

 

 

Map pocket:

 

 

 

Bottle holder:

 

 

Draft Analysis on each part:

 

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 element where the deviation from the draft direction at any point, corresponds to specified values.The draft analysis button within CATIA V5 will helps you quickly gather the draft angle on multiple surfaces without the need for tedious manual measurements.

 

 

 

 

 

Creation of engineering features:

 

Engineering features are created on the B surface after the part is made into a closed body.These attachments features are the one which help us to attach or fit the part into another part which in this case is attaching the inner door panel to the outer door panel.  

 

 

Intersection Errors while joinig body parts.

 

 

Finally after all the parts are made into solid parts along with the necessary attachment features it is then assembled together as a product.