Advanced Sheet Metal Design Using NX Cad Challenge_2_Box Assembly

REPORT

DESIGN AND DEVELOP A BOX ASSEMBLY

OBJECTIVE: The objective of the project is to design and develop the Box assembly model in sheet matel workbench by using NX CAD, and to understand the design methodology of sheet metal, features and commands.

INTRODDUCTION:

The term “sheet metal” refers to any metal that can be formed into flat pieces of varying thicknesses. Thick metals are called plate. Metals used in the sheet metal industry include cold rolled steel, mild steel, stainless steel, tin, nickel, titanium, aluminium, brass, and copper.

There are six major types of sheet metal material, each with its own unique advantages:

• Alloy steel.
• Stainless steel.
• Carbon steel.
• Tool steel.
• Galvanized steel.
• Aluminium.

MUFACTURING PROCESS:

When making sheet metal, however, companies often use one or more of the following forming processes.

1) Curling: Curling is a sheet metal forming process used to form the edges into a hollow ring. Curling can be performed to eliminate sharp edges and increase the moment of inertia near the curled end. Other parts are curled to perform their primary function, such as door hinges.

2) Bending: Metal bending is a process by which metal can be deformed when applying force to the subject, which causes it to bend at an angle and form the anticipated shape, which often results in it being in a 'V' or a 'U' shape. A press brake is a tool used in order to bend sheet metal and uses a punch and die to do this.

3) Ironing: Ironing can be accomplished during deep drawing or performed separately. The process uses a punch and die, forcing the metal sheet through a clearance that will act to uniformly reduce the entire thickness of the workpiece to a certain value. As with bending, the deformation does not reduce volume.

4) Laser Cutting: Laser cutting fabrication uses a high-power beam of light (laser) to cut out flat and thin sheets of metals. The process is directed by optics and computer numerical control (CNC) technology, which accounts for the high precision of laser cut parts.

5) Hydroforming: Hydroforming (Sheet Hydroforming) is a specialized deep draw process that uses high-pressure rubber to shape and form metal workpieces. In sheet hydroforming, a metal sheet is placed over a die before highly pressurized water forces it down and makes it conform to the shape of the mold.

6) Punching: Metal punching is the process of impressing a form on a surface by pressure or percussion with a steel punch tool. In the metal punching process, the material is removed from a piece of sheet metal by applying a great enough cutting force. The metals that can be punched are different: steel, iron, copper, and aluminium.

DESIGN METHODOLOGY AND APPROACH:

The below flow chat shows the methodology or approach for this model:

COMMONDS USED FOR DEVELOPED THIS MODEL:

The following commands using while developing this model are listed below-

1) Tap

2) Normal cut

3) Bend

4) Flange

5) Unbend

6) Hem

7) Dimple

8) Bead

9) Corner break

1) Tab Command: Tab command is use to given the thickness of the profile as per the required dimensions.

2) Normal cut: This is the command which help to remove the material as per the sketch profile, it is perpendicular to the sheet and it will follow the sheet metal shape.

3) Bend: This command helps to bend the sheet at particular place with given dimensions.

4) Flange: This command creates the flanged as per required edge at specified dimension. In this also there will be different option to give relief.

5) Unbend: This command helps to the model to bring it in initial stage before bending without losing the bending operation, which help to achieved some cuts and holes or some specified patter, which is difficult to achieved in bend position.

6) Hem: This command helps to join the two sheet matel without any welding or mastics operation.

7) Dimple: This is the command which helps to create a emboss type structure on the sheet by giving specified dimension as per the requirement.

8) Bead: Use the bead command to lift material along the contour of a sketch that simulates a stamping tool. Beads can also be created to stiffen sheet metal part.

9) Corner Break: This command helps to giver the chamfer or fillet at given dimension for the smooth manufacturing operation.

STEPS FOR MODEL BOX ASSEMBLY:

1st step): Create the sketche of dimension of 200 mm x 150 mm and by using Tab command thicken the sketch at 1 mm.

2nd step): Create flange of height 200 mm of height at two side edges and 70mm at the egde of created flange.

3rd step): Need to create hem between 2 flange to join together

4th step): Next we have to create sketch on top open area by creating datem palne at the distance of 204mm. After creating sketch using tab command thicken the sketch at 2 mm downward. And created the flange at the side edges.

5th step): New sketch has to created on the hem flange face and thicken the sketch of 1 mm. Then using flange operation create flange and open loop flange.

6th step): Unbend the created flange and loop flange and created the sketch for cutting the material as per requirment. By using normal cut command removed the material. Once material removed again we need to bend it by using rebend command.

7th step): Next created the sketch at top surface and using Tab command thicken the material of 1 mm. Created the flange and open loop flange on the outer edge.

8th step): Unbend the flange and loop flange and created the sketch as per requirement and by using normal cut command removed the material. At the final rebend the flange and open loop flange. Model is finished.

DIFFERENT VIEW OF MODEL:

CONCLUSION:

In this project we complete the box assembly model by using different command of sheet matel operation using NX Cad. Creating sheet metal model in NX Cad is very convenient and its very user friendly.In this project we learn how the hem and open loop operation coild be achieved easly by using NX software.