Designing of Sheet Metal Bracket - Using NX CAD
DESIGNING OF SHEET METAL BRACKET - USING “SIEMENS NX CAD”
Objective:
The main objective of this project is to design a sheet metal bracket using the - “Siemens NX CAD” software.
Introduction:
Sheet metal:
Sheet metal is metal formed into thin, flat pieces, usually by an industrial process. Sheet metal is one of the fundamental forms used in metal working, and it can be cut and bent into a variety of shapes.
Thickness can vary significantly; extremely thin sheets are considered foil or leaf, and pieces thicker than 6mm (0.25 inch) are considered plate, such as plate steel, a class of structural steel.
Sheet metal is available in flat pieces or coiled strips. The coils are formed by running a continuous sheet of metal through a roll slitter.
There are many different metals that can be made into sheet metal, such as aluminium, brass, copper, steel, tin, nickel and titanium.
Sheet metal is used in automobile and truck (lorry) bodies, major appliances, airplane fuselages and wings, tinplate for tin cans, roofing for buildings and many other applications.
Bracket:
A bracket is an architectural element: a structural or decorative member. It can be made of wood, stone, plaster, metal, or other media. It projects from a wall, usually to carry weight and sometimes to "strengthen an angle".
In mechanical engineering a bracket is any intermediate component for fixing one part to another, usually larger, part. What makes a bracket a bracket is that it is intermediate between the two and fixes the one to the other. Brackets vary widely in shape, but a prototypical bracket is the L-shaped metal piece that attaches a shelf (the smaller component) to a wall (the larger component): its vertical arm is fixed to one (usually large) element, and its horizontal arm protrudes outwards and holds another (usually small) element. This shelf bracket is effectively the same as the architectural bracket: a vertical arm mounted on the wall, and a horizontal arm projecting outwards for another element to be attached on top of it or below it. To enable the outstretched arm to support a greater weight, a bracket will often have a third arm running diagonally between the horizontal and vertical arms, or the bracket may be a solid triangle. By extension almost any object that performs this function of attaching one part to another (usually larger) component is also called a bracket, even though it may not be obviously L-shaped. Common examples that are often not really L-shaped at all but attach a smaller component to a larger and are still called brackets are the components that attach a bicycle lamp to a bicycle, and the rings that attach pipes to walls.
Sheet metal bracket examples are shown.
Design Approach:
Description:
The following tools and features of siemens NX CAD are used in the casing design,
Sketch:
This feature is used to create 2D drawings along the required planes and faces.
Contour flange:
Use the contour flange command to create a flange by extruding a sketch along a vector, or by sweeping a sketch along an edge or chain of edges. NX adds bends automatically using the default bend radius value. To use a different bend radius value, draw arcs in the section, or change the default bend radius value.
We can use the contour flange as the base feature of a new sheet metal part, or add the contour flange as a secondary feature.
Normal cutout:
Use the normal cutout command to cut material by projecting a sketch onto the model and then cutting perpendicular to the faces intersected by the projection. You can use planar sketches or 3D curves to specify the section for the normal cutout.
Break corner:
Break corner command helps to create blends or chamfer on all the sharp corners or edges of a component in a single go. It simply breaks the corner into blends with some radius.
Unbend:
Unbend command is used to flatten the model through selected bends with respect to selected face. All the flanges and bends of a model are flattened using this command to add more features.
Bead:
Bead tool is used to create an embossed or engraved bead on sheet metal part using single entity or a set tangentially connected entities.
Rebend:
Rebend command helps us to restore an unbend feature to its previous bent state, along with any features added after the unbend feature.
Hole:
Hole command constructs one or more holes in the ordered environment. We can use the hole command to construct simple, threaded, tapered, counterbored, and countersunk holes.
Flat pattern:
Flat pattern feature is used to create another part view where the model becomes flat from the formed sheet metal part with all the details.
Drafting:
Drafting, also spelled draughting, also called as engineering drawing, graphical representation of structures, machines, and their component parts that communicates the engineering intent of a technical design to the craftsman or worker who makes the product.
For this project, a new drafting file is created in A4 size and a new base view is added with the flat pattern created before in 1:2 scale ratio.
Standard views of bracket:
Front view.
Side view.
Top view.
Isometric view.
Bracket draft sheet.
Conclusion:
The sheet metal bracket is designed as per the engineering standards with the help of tools and features in “Siemens NX CAD” software.