Before design of Press tool, it is necessary to understand the configuration and components of press tool. The press tool consists Punch/ Punches, Die, Punch Plate, Backup plate, Stripper, ejectors many more component. For better understand the main components of press and dies, just have a look on the given figure.
Press Working Terminology
In this Article You will learn:
Ram ( Slide) : Moving Component of press which transfer the mechanical or hydraulic force from Flywheel /hydraulic system to the Press tool for sheet metal stamping.
Shank : The shank is used as a part for installing the top die in the slide of the press machine.
Punch Holder ( Upper Shoe) : This is the upper part of die set which contains guidepost pushing. The whole upper section (generally contains Punch, punch plate) of die set is mounted on the upper shoe.
Die Holder ( Lower Shoe ) :This is the lower part of die set which contains guidepost. The whole lower section ( Generally contain die, stripper) of die set is mounted on the upper shoe.
Back up Plate : Backup plate is placed so that the intensity of pressure does not become excessive on punch holder. Its is also called Punch back plate and Pressure Plate.
Punch Plate : The function of punch plate is to hold punch in it proper relative position. Punch plate fits closely over the body of punch. It is also called Punch Retainer.
Punch : This is the main component of die assembly, which is directly or indirectly moved by press ram or slide. Punch and die act together to make a stamped part.
Bed : The bed is the lower part of press frame that serves as a table to which a bolster plate is mounted.
Bolster Plate : This is a thick plate secured to the to the bed which is used for supporting & locating the die set.
Die : Die is a female part of die block/press tool for producing the given job work in a press. Die and punch work together to make a desired shape product.
Stripper : Stripper is used for strip the metal strip from a punch or die.
Guide post & Guide post bushing : These two component of press tool guide the die set to maintain the alignment during the operation. Properly lubricated, and positioned, they improve tool operation and contribute to the produce quality products. This is also called pillar die set.
Shut Height : The distance between top of the bed and bottom of slide, with its stroke down and adjustment up.
Stroke : The distance of Ram movement from its up position to its down position. It is generally constant for mechanical presses but variable for hydraulic presses.
Press Tools Components
Press Tool components may be divided into following categories:
- Structural Components
- Working Components
- Guiding or Locating Components
- Stripping Components
- Fastening Components
- Feeding Components
Press tool Components holding working components to one another and the press. Like Upper shoe, Lower shoe, shank.
Components which actually participate in the forming a desired shape stamped part. Like Punch & Die.
Guiding or Locating Components
Guiding Components maintain accurate alignment of upper shoe with the lower shoe during the operation. Guide post sets and dowel pins are the the example of guiding components.
components which remove or strip blanks and scrap from the punch or die when operation is over. Like Stripper, push off pins, Ejectors, Knock outs.
Fastening Components hold together all parts of press tool as a unit. Like Punch Plate, Die block, All Fasteners.
Feeding Components feed the blank or metal sheet to the stamping station. These components helps to increase the rate of production.
Requirement of Press Tool Design
While designing press tool and selecting the press for a given job, following factors must be considered :
- Thickness of component
- Power requirement
- Kind of operation to be performed
- No. of operations to be performed
- Overall work size
- Speed of operation.
Press tool design should suit the type of production i.e mass production, small batch or Huge batch. Press tools should meet the following requirements:
- The press tools should ensure the demanded output, safe operation & easy maintenance.
- Press tools should be designed in such a way that possible standard components are used to manufacturing of products.
- Press tools should be designed for maximum utilization of material as well manpower.
- Working Parts of the press tools must be strong and durable and replaceable when worn out.
- Dimensional accuracy and surface finish must be within tolerances.