Design of backdoor

Aim: Design of Back Door

OBJECTIVE: Design of the Outer upper and lower panel, inner panel, and the necessary reinforcements by following the Master section with the design parameters for the given class-A surface.

The Main Parts Of The back door

• Outer Upper Panel.
• Outer Lower Panel.
• Inner Panel.
• Gas Stay Reinforcement Left and Right.
• Hinge Reinforcement LH and RH.
• Striker Reinforcement.
• Wiper Reinforcement.

Design Considerations of back door :

Rear visibility criteria: Federal motor vehicle safety standard (FMVSS) No. 111, “Rear Visibility,” currently requires that vehicles be equipped with rearview mirrors to provide drivers with a view of objects that are to their side or to their side and rear.

Rear crash regulation.

Requirement of sealing and its function: In order to prevent water from entering the cabin we are introducing a sealing area where the sealing flange is provided on the inner panel and rubber mounting area is provided on the body side.

Joining techniques: To join inner and outer panels the Hemming process is used and to join outer upper and lower panels laser brazing welding is used.

Hemming: Hemming is a forming operation in which the edges of the sheet are folded or folded over another part in order to achieve a tight fit. Normally hemming operations are used to connect parts together, to improve the appearance of a part, and to reinforce part edges.

laser brazing welding:

Joining methods, in which the brazing solder is melted with the help of an industrial laser, have been used mainly in the mass production of vehicle bodies. There, laser beam brazing is mostly used for joining galvanized metal sheets or lightweight components made of aluminum, but also for other brazing material. Laser automobile brazing is usually realized with a brazing optic that is integrated in a robot. The laser beam is guided along the joint where it melts the brazing solder.

Gap and flushness requirement: Mastic Seals: Mastic Seals place b/w Inner and outer panel to reduce noise, vibration, and harshness. Every Mastic will have an effect of 80mm Dia. The inner and outer panel gap is 4 to 5mm. 0.2mm gap is required for the Hemming and that gap will be filled by sealed past.

Adding reinforcements and stiffener pad: reinforcements are added were and all the weight is added. On the inner panel, we have Hinges and striker, which are attached to the inner panel so due to this attachment the strength of the inner panel is going weak. In order to strengthen the inner panel reinforcements will play a very important role. A stiffener pad is a sponge-like material place b/w Inner and outer panel to reduce vibrations.

Emboss definition: Embosses are provided in the inner panel of the hood assembly. This helps in the weight reduction of the hood and also dissipates the force during the collision. Force dissipate is shown in the figure.

TOOLING DIRECTION:

The Tooling Direction for the inner panel is derived using bisection lines of the part from two sides.

Draft Analysis:

Draft analysis is a method of checking the draft angle on various faces of a part with a particular direction.

It should be more than 7 deg for aluminum for hard metals, min draft angle is 10 deg.