Design of backdoor

AIM:-

Using the provided styling surface to come up with a back door and using appropriate design methodologies and make the necessary reinforcements and emboss.

Introduction:-

A door is a hinged part which is used for entry and exit of the vehicle which are located next to the passenger seat which provides access to the luggage compartment. In different cars it’s will called with different names backdoor, tail gate, rear door and trunk it depends on type of model produced or designed. In the most of the cars, these back doors are located next to the passenger seat which provides access to the luggage compartment. In the most of the cars, these back doors are operated with the help of gas stay which in turn reduces the effort required to the left the door. Some luxury cars have powered trunk lid system hatchback or station wagons are sold 3 doors or 5 doors models. In this case, the rear hatch is classified as door this is because it enters the passenger compartment. The naming is mainly used in Europe countries. In case of safety, the backdoor designed should meet the safety requirement of the rear collision. The back door is attached with the body of the car with some rubber to protect it from the water entry to cabin. And the inner and outer panels are attached with the help of mastic sealants. Here we provided the reinforcement for the hinge, gas stay, wiper and latch& riker mountings of the back door for better protection.

Types of backdoor based on working positions:-

The door or opening of a cargo area may be hinged at the top, side&bottom. If the door hinged in the bottom it is called tailgate

1. Top mounted
2. Side mounted
3. Bottom mounted

1.Top mounted:-

This type of back doors is used station wagon, pickup trunk and some of the spot utility vehicles, today’s modern cars use top mounted tailgating system which are both powered and also gas stay supported. These top mounted tailgates provide greater rear visibility compared to side mounted or backdoor which have center pillars in it.

2.Side mounted:-

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 barndoors are 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. This door also have accidental head impacts. It is a lot easier to load and unload items in the side mounted doors.

3.Bottom mounted:-

This bottom type backdoor systems are used in the car type such as car, pickup truck and some luxury 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 stay 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 lift gate 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 assembly, PTG main switch. When the switch is pressed in 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.

The different panels or regions are as follows:

1. Inner panel

2. Outer upper panel
3. Outer lower panel

Total no. of parts in Backdoor are:

• Backdoor outer panel (upper)
• Backdoor outer panel (lower)
• Backdoor inner panel
• Hinge reinforcements (left and right)
• Gas stay reinforcements (left and right)
• Latch and striker reinforcements (left and right)
• Wiper motor reinforcements (left and right)

Roof and roof rails design:-

Inner panel:-

The inner panel is a component which is used for strengthening the door and it is one of 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 the assembly cost and eliminates any fit ability problems

Outer panel :-

The outer panel of the back door is similar to the 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 the provisions for the tail lamp, rear fog lamp and also has the provision license plate mountings. Most of the hatch back cars have the provision for wiper motor.

Hinge Reinforcement:-

Hinges support the weight of the whole backdoor. Hence the reinforcements are provided here too. Emboss is designed such that the hinges should be operated freely. The electrical wiring looms are though the holes along the periphery to keep them hidden. The back door opens minimum number of times when compared to the side doors. The opening and closing no. of cycles will be less in opening. This reinforcement is provided for better strength to the hinge mounting. The thickness provided is 1.5mm. this reinforcement created as assembly or two mirrored part for both sides left and right.

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 reinforcement with a thicker sheet. These reinforcement provided for the better safety to the gas stay mountings. The thickness provided is 1.5mm. this reinforcement created as assembly or two mirrored part for both sides left and right.

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 thickness provided is 1.5mm. this reinforcement created as assembly or two mirrored part for both sides left and right. The embosses helps stiffening the panel and act like local reinforcements. Extensions are provided around holes are attached to outer panels and acts as crumple zone elements in case of rear impacts.

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. The thickness provided is 1.5mm. this reinforcement created as assembly or two mirrored part for both sides left and right. One hole is created in center for clamping. Another purpose of the emboss design is to distribute impact force towards hinges and latch assembly which are reinforced and can absorb them.

hemming:-

hemming is the process of doing rolling of sheet of the outer panel around inner panel of the back door to give strength to the backdoor. these outer and inner panel will be spot welded or mastics will added to it for giving assembly.

hemming relief:-

hemming relief is given at the corners of the hemming for better protection. in sudden decrease or bend of the hemming can cause the stress concentration or breaking to the outer panel of door. by providing the relief we can give better hemming.

Final assembly:-

Draft analysis:-

Conclusion:-

As per given dimensions and master sections we created the backdoor and all back door assembling parts of the car. And we provided reinforcements to backdoor mountings and also provided the embosses to the inner panel.