Design of backdoor
AIM:
I am using the provided design surface to create a back entrance, applying appropriate design processes, and implementing the necessary reinforcements and embossing.
Backdoor/Rear door/Tailgate/Trunk:
A door is a hinged part used for the entry and exit of vehicles. Backdoors are a type of vehicle door located next to the passenger seat to provide access to the luggage compartment. In most cars, these back doors are operated with the help of a gas stay, which reduces the effort required to lift the door. Some luxury cars have powered backdoors driven by an electric motor. This system is also called a powered trunk lid system. Hatchbacks or station wagons are sold as 3-door or 5-door models. In this case, the rear hatch is classified as a door because it enters the passenger compartment. This naming convention is mainly used in European countries. In terms of safety, the design of the backdoor should meet the safety requirements for rear collisions.
Types of Backdoor based on working positions:
The cargo area door or opening may be hinged at the top, side, or bottom. If the door is hinged at the bottom, it is called a tailgate.
1. Top-mounted
2. Side-mounted doors
3. Bottom type
1. Top mounted:
This type of back door is used in station wagons, pickup trucks, and some sport utility vehicles. Modern cars today use top-mounted tailgating systems that are both powered and gas-stay-supported. These top-mounted tailgates provide greater rear visibility compared to side-mounted or back doors which have centre pillars.
2.Side mounted door:
As the name signifies the side mounted doors are the one which is used in the van type MPVs, SUVs, pickup truck vehicles. These side mounted doors or barn doors are a lot easier compare to top mounted doors. These doors are generally smaller in size and can be easily accessed. These doors are more convenient for the goods handlers for long pipe and lengthy components where one door is kept open. These door also save accidental head impacts. It is a lot easier to load and unload items in the side mounted doors
3.Bottom type:
This bottom type type backdoor system are used in the car type such as car, pickup truck and some luxuary SUVs. These are the most convenient type of back door in which the bottom split is used as a support or even as a table for the tour going people.
Types based on Working Mechanism:
1.Gas Stays type.
2.Powered Lift system.
1.Gas Stay type:
Gas Stay type backdoor is an ideal and most commonly used tailgate mechanism from lower segment car to luxury car segment. The ideal components of tailgate consist of a hinge, door, gas stay and some rubber beadings for sealing of door.
2.Powered Lift System:
Power trunk lift system is another sophisticated way of trunk or liftgate opening mechanism which is to automatically open and close of the trunk and release of the latch by the touch of a bottom. Powered trunk Lift system consists of a power latch, anti pinch switch, PTG assly, PTG main switch. When the switch is pressed in the compartment or outside the power latch releases the latch and the entire backdoor is opened. The anti pinch switch is located in order to avoid accidental hand insertion during the operation of the door.
Manufacturing methods:
Recently, there have been two approaches to reducing automobile weight. One is by using material lighter than steel and the other is by redesigning the steel structure. Althrough the former seems very effective, it is very expensive so that it may only be used for an expensive automobile industry is trying to use steel, which is not costly and recyclable. Light weight steel can be achieved by improving the performance of the structure or adopting by improving the performance of the structure or adopting new manufacturing techniques. One of the efforts is the ULSAB (Ultra Light Steel Auto Body) concept.
ULSAB suggests three main weight reduction techniques such as hydro forming and the Tailor Welded Blank (TWB)
Tailor Welded Blank:
A Tailor Welded Blank is a blank that is compared of two seperate pieces of sheet metal that have been welded together prior to stamping. Tailor Welded Blanks allow the welding of the different grades, different thickness or different corrosion coating together in order to give the properties needed in differeent areas, without increasing the number of tools needed to form the part and eliminating the fit ability concerns. They also allow a high degree of flexibility in designing parts and large blanks can be formed from much smaller sheets. The use of Tailor Welded Blanks would reduce the weight of the car. Having the ability to selectively place different thickness of materrial would result in weight reductions. An example of this production is the door inner panel. The only strength requirement on a door inner is in the region where the hinges attach to the panel
The Different panels or regions are as follows:
1. Inner Panel.
2. Outer Upper Panel.
3. Outer Lower Panel.
Backdoor Assembly:
1. Inner Panel
2. Outer Panel
3. Hinge Reniforcement.
4. Gas Stay Reniforcement.
5. Wiper Motor Reniforcement.
6. Latch and Striker Reniforcement.
1. Inner Panel:
The inner Panel is a component that is used for strengthening the door and it is one of the most important components on which all accessories are mounted like hinges, glass guide channel, mounted trim, latch etc.., The possible method is the integration method. In the integration method, the part is stamped out of a single blank. This reduces the number of tools needed and the assembly cost and eliminates any fit ability problem.
2. Outer panel:
The Outer panel of the back door is similar to other BIW components where it is the aesthetic part of a vehicle. The coating provided is of multi stage which has the property of scratch resistance, rush prevention and smooth and attractive finishes. The Outer panel also has provisions for the tail lamp, and rear fog lamp and also has the provision for licence plate mountings. Most of the hatchback cars have the provision for wiper motors.
3. Hinge Reinforcement:
Hinges support the weight of the whole backdoor. Hence reinforcement are provided here too. Emboss is designed such that the hinges should be operated freely. The electrical wiring looms are through the holes along the periphery to keep them hidden.
4. Gas stay Reinforcement:
An angled or Diabolic emboss is provided for the gas stay mounts. The angle makes it easy to be machined and stamped. It is reinforced with a thicker sheet.
5. Wiper motor Reinforcement:
A dedicated space near the window is left for wiper motor assembly. A cavity is placed in the middle of the panel for the necessary components in the assembly as well as other accessories.
The holes or cavities are placed strategically to accommodate wiring looms, tail lamp mounts, and other accessories. Embosses help stiffen the panel and act like local reinforcements. Extensions are provided around holes which are attached to outer panels and acts are crumple zone elements in case of rear impacts.
6. Latch and striker Reinforcement:
At the bottom of the latch and striker assembly. Generally, a key-operated or automatic remotely controllable locking mechanism is used to keep the door closed and open.
Another purpose of the embossed design is to distribute impact force towards hinges and latch assembly, which are reinforced and can absorb it.
Final Assembly:
Conclusion:
By applying solid and sheet modelling methodologies and adhering to engineering standards, the design of the backdoor was completed using NX CAD.