Frontal BIW enclosure/hood design using NX CAD
HOOD DESIGN USING SIEMENS NX 12:
HOOD or Bonnet is located at the frontal portion of an automobile through which the engine compartment can be accessed.it is like a door that opens and closes by utilizing hinges located at the back end of the panel.
FILES LINK:
https://drive.google.com/file/d/1zQfm8mUDRjXL_BBzUBtQKgY4-7DWSzX-/view?usp=sharing
Design considerations for the hood
1. The hood design should follow a master section that meets all the safety and structural requirements.
2. The hood should be designed in such a way that in case of a crash it should dissipate the crash forces towards the hinges away from the passenger compartment.
3. The opening and closing of the hood should be seamless without any interruptions.this can be achieved by placing the latch and striker mechanism at an optimum distance from the hinges
4.in In case of a crash maximum amount of force should be absorbed as it is the frontal part of the car.
5.the design should be in a manner that easy access and serviceability of the engine compartment is achieved.
6. It should be aerodynamic and aesthetic to reduced drag force and looks appealing.
Hood
my design of hood employs a V shape design which effectively dissipates the crash forces away from the passenger compartment and also satisfies the structural requirements.
embosses are provided at various possible locations to increase the strength of the hood
MASTICS: mastic is an adhesive used to fill the gap and join the inner and outer panel.
mastic points also increase the strength around 80 mm diameter from where they are placed
HEMMING: HEmming is a sheet metal operation that is widely used in the automobile sector because welding or any joining operations can not be done on styling parts as it may affect the aesthetics of the car.here the outer panel is rolled around the inner panel which effectively joins the two of them without affecting the aesthetics. the gap between the hem is filled with a mastic sealant
RELIEFS: Reliefs are provided at the front and side portions of the panel for smooth rolling operation.so that no tearing of the sheet happens when roller passes through certain portions.
ASSEMBLY: After the HEMMING is complete the latch and hinges are mounted on to the panel into their respective embosses.which are used to mount the hood on to the body of the car
Hinges: the hinges acts a pivot point for the opening and closing of the hood
latch: the latch engages and disengages utilizing a striker mechanism thereby acting as a lock for the hood.
REINFORCEMENTS: reinforcements with 1.5 mm thickness are provided into the embosses to add strength to the components assembly
LATCH POSITIONING: The latch should be positioned in a way that it should not interfere in opening and closing of the hood
this is done by positioning it at a distance which is tangential from the center point on the axis of the hinge.
DRAFT ANALYSIS