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Power Presses

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Power Presses

A press is a machine with a stationary bed and a guided slide (or ram) that reciprocates toward and away from it.

Presses are stroke-controlled devices.

Presses can be:

  • Manual (arbor press, screw press, kick press)
  • Power (mechanical or hydraulic)

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Mechanical Power Presses

Mechanical - Energy is stored in flywheel

Fast Production Rates

Capacity to 6,000 tons

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Mechanical Press

Parts

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Press Capacity

Tonnage

Shut Height or Daylight

Physical Size

Stroke

Adjustment of Ram

Speed - SPM

See note on shut height.

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Note

The distance from the top of the bolster to the bottom of the slide (SDAU) is sometimes called the “shut height” but “die height” is the better term.

Be sure you know what shut height they are referring to.

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Drive Configurations

Direct Drive

Single Gear Reduction

Multiple Gear Reduction

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Hydraulic Press

Controlled Stroke

Smooth operation

Full tonnage available at top of stroke

Easy to control

High Capacity

Can have 50,000+ tons

(236 locomotives, See:https://en.wikipedia.org/wiki/Heavy_Press_Program)

Hydraulic presses can reverse mid-stroke

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Hydraulic Press

Air/Oil presses

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Servo Electric Press

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Press Styles Gap or C-Frame

Gap Frame Presses

OBI - Open-Back Inclinable

OBS - Open-Back Stationary

ABS - Adjustable Bed Stationary

Horn Press

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Deflection

C-Frames will deflect.

The result is misalignment of punch and die.

How much they deflect is the question.

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Press Styles (Straight Side Press)

Limits die accessibility.

Deflection is in the direction of punching.

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Clutches & Brakes

Connect/disconnect the crank mechanism to/from the flywheel

Stop the motion

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Double Action Presses

For deep drawing operations

Have separate slides for

  • Drawing
  • Blankholding

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Ancillary Press equipment

Straighteners

Apply alternating compressive and tensile stresses on the material to relieve the plastic deformation that was developed during coiling.

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Press Feeding

Die sets may be designed to accept blanks or coil stock.

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Uncoilers

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Strip Feeder

Types include:

Air Slide Feeds

Hydraulic Slide Feeds

Motor-Driven Slide Feeds

Roll Feeds

Can be push feed

Or

Pull feed (for thin material)

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Scrap Cutter/Chopper

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Die Cushion or Pressure Pads

Can be used for blank holder pressure

Can be used for liftout or knockout purposes to remove stampings from the die.

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Fourslide Press

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Press Brake

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Power Press Safety

Guarding

Operation

Danger in Setup

  • Close Tolerances
  • Lots of Force

Lockout/Tagout

Eliminating Sources of Energy (Die Safety Blocks)