TYPES OF DIES BASED ON CONSTRUCTION

TYPES OF DIES BASED ON CONSTRUCTION
1 SIMPLE DIES:

Simple dies or single action dies perform single
operation for each stroke of the press slide. The operation
may be any one of the operations listed under cutting or
forming dies.

2.COMPOUND DIES:
In compound dies,two or more cutting operations
may be performed at one station by one stroke of the press.
Compound dies are more accurate and economical in mass
production as compared to single operartion dies.
For example, a washer component is made by one
stroke of the press in compound die. The washer is produced
by simultaneous blanking and Piercing operations.

Die construction:
Here the blank punch cum piercing die is
mounted on the bottom of the bottom plate which
is bolsted with machine bed. Blank die and piercing
punch are mounted on the top plate which is mounted
on the press ram. A knockout is placed between
blankdie and piercing punch which is used for to
eject the component from the die. A stripper plate is
held with blank punch which is to strip out strip from
the punch after the operation completed.

















3.COMBINATION DIES:
In combination dies more than one operations may be
performed at one station. It is differs from compound dies.
In combination dies cutting and non- cutting operations done
at one station by one stroke of the press.


1.BACKUP PLATE 2.PUNCH HOLDER PLATE
3.BLANK PUNCH CUM DRAW DIE 4.KNOCKOUT
5.STRIPPER PLATE 6.DIE PLATE 7.PRESSURE PAD
8.FORMING PUNCH 9.BASE PLATE.

A cup shaped component is produced in combination dies.
Blank punch cum draw die is mounted on the punch holder and
it is fastened to the press ram.Knockout is held inside the blank
punch which is push out the part from the draw die. A stripper
plate is also held with blank punch.
Blank die and inner size form punch are mounted on the
base plate which are held on the press bed. Pressure pad is
placed between blank die and form punch, which is used for
giving uniform drawing and also to eject the cup from the
form punch.
The sheet metal is placed between the blank punch
and die. During operation, the blank punch first cut
the outer of the blank in sheet metal and also
to form as a cup. Pressure pad helps the uniform and
rigid formation of cup. A diecushion is permanently
mounted under the press machine bed, which helps
uniform drawing and also to eject the part after return
stroke of ram.



4.PROGRESSIVE OR FOLLOW DIE:
Progressive die has a series of stations. At each station
, an operation is performed on a workpiece during a stroke of
the press.Between stroke, the piece in the metal strip is
transferred to the next station.A finished work is made at
each stroke of the press.



For example, in progressive die a rectangle blank part
have two round holes at corners and a one square hole at
the center.
Here the component is completed for three station.
At first station,two coner holes to be pierced on the sheet metal.
At second station,first the pilots are correctly guide the already
pierced holes and then center square hole is done one the
sheet metal.At that same time,two corner holes are pierced out
at first station for next component(second part).
Then the strip is moved at station-3. In this stage,
the component is blanked out from the sheet metal. At the
same time,in first stagte,third part corner holes are produced
and in second stage,the second part have center square
hole piercing.The above stage operations are done
simultaneously.



5.TRANSFER DIES:
Unlike the progressive die where the metal stock is fed
progressively from one station to another. But in transfer dies,
the already out blanks are fed mechanically from
station to station.


6.MULTIPLE DIES:
Multiple or gang dies produce two or more
workpieces at each stroke of the press. A gang or number
of simple dies and punches are ganged together to
produce two or more parts at each stroke of the press.

7.INVERTED DIES:
In generally, in punch holder plate punch is held,
which is fastened to the ram. Die is fitted with die holder,
which is held on press bed.
But in inverted dies, the punch and die are to be
interchanged. Punch is held in bed and the die is fastened
to the ram.