Advanced Sheet Metal Design Using NX Cad Challenge_2_Box Assembly
DESIGN A BOX ASSEMBLY BY USING NX12
Objectives: To learn sheet metal design process and to design a sheet metal box assembly by using Siemens NX
Introduction: Sheet metal is simply metal formed into thin and flat pieces. It is one of the fundamental forms used in metalworking and can be cut and bent into a variety of different shapes. Countless everyday objects are constructed of material. Thicknesses can vary significantly, although extremely thin thicknesses are considered foil or leaf, and pieces thicker than 6 mm (0.25 in) are considered plate.
Design methodology: in the sheet metal box assembly design process we used different tools, features like tabs, flanges, bends, dimples, re-bend, etc. The design methodology used for this project step by step procedure is shown in below flow chart
Description: In the box assembly project l used repeated tools for making box assembly design. All steps are clearly described in below following steps
Sketch: Sketch is the fundamental base element of design for any sheet metal component. Most of the features require a sketch. For box, assembly Create a sketch in the “XY” plane and draw a rectangle centered at the origin with given dimensions
Tab: create a base feature by extruding a sketch along a vector by a thickness value or adds material to the planer face. Additional selection can be added to generate bends as part of the base feature. For box assembly design creating a first rectangular metal with 1mm thickness. (Home tab: basic gallery -tab)
Flange: Adding a flat flange at an angle to a planar surface and adds a bend between the two. For sheet metal box assembly design adding flanges perpendicular to the base tab with a given length in pdf as shown below figure (Home tab: bend gallery– flange)
and again add two flanges at right edges perpendicular to the just created flanges with 70 mm length like as shown in figure
Closed corners: closes a corner where two adjacent flanges meet by extending the bends and flanges or between the tab and flange which is perpendicular or at any angle. for this project, the closed core is used on both sides of the bottom flanges(home tab: corner Gallary-closed corner)
flanges for fastening: before applying hem flange I create a flange with the length of 0.02 for the purpose of the fastening
Hem flange: modify the model by folding the edges of a sheet metal flange over onto itself for the purpose of safe handling or to increase the edge stiffness. (home tab: bend Gallary-hem flange)
Mirror body: copies a feature and mirrors it across a plane. for box, assembly design selects the body and selected the "YZ" plane.
unite: combines the volume of two or more bodies into a single body. (Home tab: design features Gallary-more-unite)
Dimple: lifts an area of the model inside a sketch that simulates a stamping tool. for this project draw a sketch on the front view of the model and then apply depth & reference as shown in the below figure. this dimple is mirrored along the XZ plane to get the same feature on the other flange of the opposite side (Home tab: punch gallery-dimple)
Also added a dimple on the bottom face of the model and which the material inside the box as shown in the figure;
Bead: create a solid using a path and a cross-section shape. For box assembly design beds are applied in symmetric positions as shown in the below image and mirrored along with XZ, YZ plane to get four beads on each side of the corner. (Home tab: punch gallery-bead)
Hem flange: Applying a hem on the top edge of the flanges on four sides
Lid designing: Before creating a lid add a new plane. take a datum plane with 203mm offset from the"XY" plane and draw a sketch on a new plane as shown in the figure,
after sketching apply a base tab with 2mm thickness final output of the lid as shown fig.
flange: Create a flange on both sides with a length of 3mm downwards for covering the box as shown in figure
Tab creation for hinge: Draw a sketch on the right view facing of the model with 55mm length and 20mm width
Break corner: Rounds chamfer a sharp corner of a tab flange. For the box, assembly design Apply the broken corner to the edge of the sheet metal with a radius of 10mm (Home tab: corner gallery-break corner)
flange: Add a flange on the top edge hinge tab with 4mm length and at an angle of 40 degrees apply and again do the same process on just created flange
Hem flange: An open hem flange of radius 5mm and at an angle, 325 degrees is added at the end of the flange as shown in figure
Unbend: flatten a bend and the material adjacent to the bend. in the unbending dialog box select stationary face (Home tab: form -unbend)
Normal cut-out: cuts material by projecting a sketch onto the model and then cutting perpendicular to the faces intersected by the projection. The box assembly design draws a rectangle with 14mm. (Home tab: features gallery-normal cutout)
Re-bend: restore an unbend feature to its previous bend state along with any features added after the unbend feature
Mirror: copies a feature and mirrors it across a plane. For box, assembly designing select the hinge and its corresponding sketch select YZ plane as mirror plane apply to validate (home tab -feature gallery-more-mirror feature
Tab creation for upper hinge: To create a base tab on top of the lid for the upper hinge with a 1mm thickness
Hem flange for upper hinge: Add a flange on the front edge just before created the base tab. After that add an open-loop hem
Unbend&Normal cut-out: After applying hem flange unbend it. sketch a rectangle with a 14 mm distance at a flat stage and apply normal cut-out
Re-bend: restore an unbend feature to its previous bend state along with any features added after the unbend feature
Flat pattern: creates a flat pattern feature from the formed sheet metal part. (Home tab-flat pattern gallery)
Drafting: After the design is complete, the execution of the manufacturing component requires a technical drawing of the components with the provided and with accuracy. The details like annotations, bend table can be added as per requirement.
DIFFERENT views BOX ASSEMBLY:
Top view of the sheet metal box assembly:
Front view of the sheet metal box assembly:
Right view of the box assembly:
Tree images of the box assembly
Conclusion: I have done this project, successfully by using NX tools in Siemens NX