Sheetmetal Trg

8/12/2019 Sheetmetal Trg

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Introduction to Sheetmetal

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Introduction:

•For complicated shapes

•easy to reshape & secondary operation

•Easy & Mass production

•Different grade materials

•Cheaper cost

•Repeatability & Interchangeability




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Design Points to be considered:

•Design indent & Functionality

•Rigidity - Strength

•Burr side

•Grain direction

•Heat treatment

•Surface finishing & coatings






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Terminology:

• Strip layout

• Pitch

• Burr side

• Radius side

• Burnished band

• Minimum bend radii

• Flatness

• Grain direction

• Bend allowance

•Development Length




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Break

RadiusBlank

Burnished band

* Blank generally takes Die profile dimension

Burr




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Break

Radius

Piercing

Burnished band

** Pierced hole generally takes Punch profile’s dimension

Burr




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Production Process:

1. Press tools:

• Single stage

• Multiple stage

• Progressive tools

• Compound tools

• Combination tools

• Drawing dies

• Fine blanking dies

2. Press Brakes

3. CNC Presses




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1. Single Stage Tool:

• Only one operation•eg Blanking or piercing

2. Multi-Stage Tool:

•Component needs more than one operation

•eg Blanking, piercing, bending etc. done in

separate tools, stagewise.

Processes




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3. Progressive Tools:

• Component needs more than one operation

• e.g. Blanking, piercing, bending etc. done in same

tool, as stage wise.

• Stock is fed into tool via pneumatic feeders.

• Plain strip converted to Product at the end of the

stroke

• Complex die design, but suitable for mass

production.

Processes




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4. Compound Tools:


• Single stage;

• Blanking & piercing done simultaneously

• Dimensional accuracy, and Flat components

• Complex design; More Die Cost;

• Suitable for mass production.

Processes




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5. Combination Tools:


• Multi stage tools; similar to progressive tools

• Blanking, piercing, forming operations carried out

in stage wise.

Processes

6. Drawing Dies:

• Shallow drawing - One step draw process

• Deep drawing - More than one drawing.




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7. Fine Blanking Tools:

• Straight outer surfaces with negligible radius and

minimum burr.

• This is achieved through ‘V’ shape pressure pads

and counter punch.

• Similar to Compound dies

• Triple action press is needed

• Suitable upto 12 mm sheet thickness.

Processes




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Press Brakes

• For forming operation

• Bend angles can be varied easily.

CNC Presses:

• standard punches & tools

Processes




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Advantages:• Accurate & precision components

• Only possible in Sheetmetal (e.g. switch gear components)

• Mass production.

•Intricate & complicated shapes can be achieved

Disadvantages:

• Costly tool maintenance

• High tool down time

• Needs skilled operators for die setting & maintenance.




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Design tips….

Avoid sharp edges

Mini. Internal bend radii = 1 sheet thickness

Strength & FS

Standard sheet thickness

Assembly constraints & Safety

Keep in mind, Closer the tolerance, Higher the cost

Documents

Sheetmetal Trg