看看老外的Press basic

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This class introduces common presses, their main components and functions.

Class Outline	Class Objectives
Objectives What Is a Press? What Is Stamping? Major Press Components The Die Set The Gap-Frame Press Straight-Side Press The Mechanical Press The Hydraulic Press Capacity of a Press Range of Press Capacities Press Forces The Press Brake and Turret Press The Arch Press and Horn Press Summary	Describe a press. Describe stamping. Identify major press components. Describe the die set. Identify the gap-frame press. Identify the straight-side press. Describe the mechanical press. Describe the hydraulic press. Define capacity. Relate press style to possible capacity. Describe the importance of shear forces. Identify the press brake. Identify the turret press. Identify the arch press. Identify the horn press.

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Class Vocabulary  

Term Definition
arch press  A type of press similar to a straight-side press with an enlarged bed and bell-shaped frame. The arch press can accommodate larger sheets of metal.
bed  The main foundation and supporting structure upon which the operating parts of the machine are mounted and guided.
bending  The shaping of sheet metal by straining the metal around a straight axis. A bending operation compresses the interior side of the bend and stretches the exterior side. Flanging, hemming, and seaming are all bending operations.
blanking  A shearing operation that creates a hole in sheet metal by separating an interior section. The removed piece of metal is the desired section.
bolster plate  A plate that is designed to hold in place the lower die shoe. The bolster plate is attached to the top surface of the press bed.
capacity  The specified amount of force that a press is capable of exerting near the bottom of its stroke in order to carry out a stamping operation.
C-frame press  Another term for the gap-frame press.
cold working  The shaping of metal at temperatures much lower than the metal's molten state, often at room temperature. Cold working adds certain properties to the metal, such as increased strength and improved surface finish.
crankshaft  The device in some mechanical presses that connects the ram to the flywheel.
crown  The upper portion of a press containing the drive mechanisms or cylinders that guide the reciprocating motion of the ram.
cylinder  The main drive of a hydraulic press that uses fluid to force the motion of a piston encased within the device.
deep drawing  A drawing operation performed on sheet metal that creates a hollow shape with a depth greater than its width.
deflection  The amount of deviation from a straight line or plane when a force is applied. Effective presses reduce the amount of deflection during operation.
die  The tool typically attached to the lower portion of the die set containing a recess that provides space for the shaping or shearing of sheet metal.
die set  The collective assembly of upper and lower die shoes, guide pins and bushings, and punch and die holders.
drawing  For sheet metal, a forming operation that transforms a flat disc of stock into a hollow cup with an enclosed bottom. Drawing operations can also create boxes and more intricate shapes as well.
eccentric drive  A drive that uses an offset section to power the reciprocating motion of the ram.
flanging  A bending operation that bends the edge of a part to add stiffness. Flanging most often creates a 90 degree bend in the metal.
flywheel  The main device located in the crown of a mechanical press that is attached to the power source and regulates the reciprocating motion of the ram.
frame  The structure of a press that supports the ram above the base and guides the reciprocating motion of the ram.
gap-frame press  A type of press with a C-shaped frame suspending the crown over the bed and an open portion in the front. The open front of the gap-frame press offers easy access to the die set.
horn press  A type of press with a cylindrical projection designed to position sheet metal parts for secondary operations.
hot working  The shaping of metal at temperatures close to the metal's molten state. Metal that has been hot worked is often left with a rough, scaly exterior.
hydraulic power  Power derived from the motion and pressure of a fluid, such as water or oil.
hydraulic press  A press that is driven by hydraulic power. Most hydraulic presses are driven by one or more cylinders that use fluid pressure.
lower die shoe  The lower plate of a die set that contains the cavity into which the punch shears the sheet metal.
mechanical power  Power derived from the use of solid tooling and machinery.
mechanical press  A press that is driven by mechanical power. Most mechanical presses are driven by a flywheel, crank, and clutch.
metal forming  The plastic deformation of a metal in order to produce a useful shape. Sheet metal can be formed through operations that shear, stretch, bend, or compress the metal.
open-back inclinable press  A type of gap-frame press with a bed and frame that can be tilted backwards to encourage the removal of parts after they are separated from the strip.
press  A machine with a stationary base and an upper ram that moves along a vertical axis to shear, bend, or form sheet metal.
press brake  A type of press with an open frame and wide, narrow bed. Press brakes are often used for bending operations, and they are typically manually operated.
punch  The tool typically attached to the upper portion of the die set that shapes or penetrates the sheet metal.
punching  A shearing operation that creates an open hole in sheet metal by separating an interior section. The removed metal section is discarded scrap.
ram  The main upper portion of the press that slides up and down within the press frame. The upper die shoe is attached to the ram.
seaming  A bending operation that joins the interlocking edges of two separate metal sheets together by folding them over one another.
shear force  A force that attempts to cause the internal structure of a material to slide against itself.
shear strength  The ability of a material to resist forces that attempt to cause the internal structure of the material to slide against itself.
stamping  The process of forming sheet metal at room temperature with the use of dies and punches.
straight-side press  A type of press with supporting columns in each corner of the frame suspending the crown over the bed. The straight-side press offers improved rigidity and reduced deflection.
stroke  The distance marked by the farthest ends of reciprocating vertical movement of the press ram.
turret press  A type of press with an open frame and a turret containing multiple punches. Turret presses are mostly used to perform a variety of shearing operations, and they are typically numerically controlled.
upper die shoe  The upper plate of a die set that secures the punch holder.