Advanced Sheet Metal Design Using NX Cad Challenge_7_ Metal bracket-II

DESIGN OF SHEET METAL BRACKET USING SIEMENS NX CAD TOOL

Objective

To design a sheet metal bracket by adding features with reference to the input data and by following the industrial design methodologies for manufacturing a sheet metal component.

Introduction

Sheet metal is any metal that has a thickness in between 0.4 to 6 mm and it can be obtained by any metal rolling process method (cold rolled and hot rolled). Sheet metal widely used in industries like automobile, aerospace, electronic appliance, medical, construction, furniture, etc. To utilize sheet metal to its full extent we must understand standard measurements, materials, differences in manufacturing, possible forming methods and the material properties.

Sheet metal fabrication is the process of forming metal sheets to the desired shape using different manufacturing methods.

SHEET METAL BRACKET

Brackets are connecting devices used to join two objects. In addition to creating a connection between two parts, a bracket may provide support. Some brackets, such as gusset brackets, are designed with a diagonal section that reduces the strain on the bracket and allows it to support heavier loads.

Brackets typically consist of two or more planes connected along one edge, and often to simplest way to fabricate this kind of object is to bend a flat sheet metal(blank) in two or more places: the simplest example would be adding a 90° bend to a flat rectangle with a straight profile, turning it into a bracket with an L-shaped profile. Brackets often have holes in them, either threaded or unthreaded, so that screws or other fasteners can be fed through them, but this is not a defining feature of the bracket.

Most brackets are functional, with their purpose being to connect and support objects. However, brackets can also be decorative: since brackets are often visible. Sheet metal bracket used to support objects like shelving, countertops, flooring, sections of furniture, electrical appliances and machineries.

Design methodologies

• Brackets can be made from a variety of metals, depending on certain factors, including: the load it must support, cosmetic requirements, surface finishing requirements, minimum and maximum thickness, required bending angles, and budget for manufacturing.
• To designing a sheet metal bracket, it is always important to understand the aesthetic and functional requirements of the product in every design process.
• The starting point is determining what loading your metal part will be required to hold.
• The next step is to choose best fit metal by considering, product requirements & application of sheet metal bracket. The best metals are those that offer premium quality while providing wear and corrosion resistance.
• Choosing the right shape and dimension of the bracket is another one of the crucial design consideration and will be determined by the shape of the item it is holding up but will also be affected by the load capabilities and the ease in manufacturing.
• Adding specific features to the bracket can improve strength dramatically and also can be improved by adding more profile to the metal part.
• As the main purpose of the sheet metal bracket is to joining two objects we should consider the provision cutout for screws and other fasteners while designing the sheet metal bracket.

Description

• Analyze the 2D drawing and understand how the sheet metal bracket is going to be design.
• From the given 2D drawing create the fully constraint sketch including all the features for the entire sheet metal bracket.
• Create the fully constraint sketch for the base body by following all the dimensions from the input data.
• Convert the fully constraint sketch into sheet metal part by using contour flange command.
• Remove the excess sheet metal areas from the base sheet by using normal cut command with the help of the predefined fully constraint sketch.
• All the unwanted areas are removed and applied corner break to the required edges of bracket.
• For adding features like screw holes, provision cutouts, etc. unbend the reshaped sheet metal body of bracket by using unbend command.
• By using fully constraint sketch and normal cutout command the features are added to the base sheet metal body and re-bend the sheet metal to its original shape.
• All the edges are smoothening by using break corner command with suitable curvature radius.
• Due to the complex shape of the sheet metal bracket advance flange command tool used for adding additional flanges to the base sheet of bracket.
• Again unbend the developed sheet metal body for validating the design and adding features like screw holes.
• Screw holes are positioned and punched in the sheet metal body with the help of a sketch and hole command.
• Normal cutout command used for final touchup, removal of excess material and for adding other features.
• Finally, gussets are added to edges of the of the sheet metal bracket, where ever good strength and support is required by using gusset command and thereby improving the strength of the sheet metal bracket.

FULLY CONSTRAINT SKETCH IN YZ PLANE (RIGHT SIDE VIEW)

FULLY CONSTRAINT SKETCH IN XZ PLANE (FRONT SIDE VIEW)

FRONT SIDE VIEW OF SHEET METAL BRACKET

LEFT SIDE VIEW OF SHEET METAL BRACKET

RIGHT SIDE VIEW OF SHEET METAL BRACKET

ISOMETRIC VIEW OF SHEET METAL BRACKET

RIGHT SIDE VIEW OF SHEET METAL BRACKET AFTER UNBENDING OPERATION WITHOUT GUSSETS

TOP SIDE VIEW OF SHEET METAL BRACKET

BACK SIDE VIEW OF SHEET METAL BRACKET

Conclusion

Thus an easy to manufacture, cost effective and very functional sheet metal bracket was designed with features by following the design guidelines and manufacturing methodologies.