EMBOSSING:
Embossing is the shallow forming operation in which the work piece material is stretched over a male die and made to conform to a male die surface by a mating female die surface. The finished product will have depressed detail on the other.
The major difference between embossing and forming is that the displaced pattern. Embossing is done to stiffen and strengthen a sheet metal part or to impart a raised or depressed design on the surface of the part. The circular groove on the bottom of the sheet metal part or to container is on example of embossing for stiffness and strengthening.
Embossing simple details such as stiffening ribs do not require that female die be the exact reverse of the male punch. Here the metal stretches over the punch and across the radius edge of the die face. Radii must be provide on the surface over which the metal must flows.
Detail containing pattern that are reversed in both directions require that female die be exact reverse of the male die, with allowance made for the thickness of the sheet.
Embossing is the shallow forming operation in which the work piece material is stretched over a male die and made to conform to a male die surface by a mating female die surface. The finished product will have depressed detail on the other.
The major difference between embossing and forming is that the displaced pattern. Embossing is done to stiffen and strengthen a sheet metal part or to impart a raised or depressed design on the surface of the part. The circular groove on the bottom of the sheet metal part or to container is on example of embossing for stiffness and strengthening.
Embossing simple details such as stiffening ribs do not require that female die be the exact reverse of the male punch. Here the metal stretches over the punch and across the radius edge of the die face. Radii must be provide on the surface over which the metal must flows.
Detail containing pattern that are reversed in both directions require that female die be exact reverse of the male die, with allowance made for the thickness of the sheet.
Pressure pads or ejector pins are to be providing to remove the embossed part from die depending on the size and shape of the embossed form. When embossing non-ferrous metals like aluminum, copper etc a rubber cushion can be used instead of the punch made of steel.
COINING:
Coining is the operation of pressing material in a die so that it flows into space in the detail of the die face. Coining differs from embossing. In Coining the metal flows, where as in embossing the metal does not change in thickness to great extent.
Coining operations are generally performed cold. Coining has two major advantages
1) Ornate detail can be produced with excellent surface finish.
2) Tolerances can be held to very closer values.
CURLING:-
A Curling tool rolls a raw edge of the sheet metal into a roll or curl. The purpose is to strengthen the raw edge, provide protective edge and improve the appearance of the part. The curl is often applied over a wire ring for increased strength.
Size of the curl groove in the die is same as the curl diameter on the part.
The size of the curl is determined by the metal thickness. Generally it should have a diameter of less than four times the metal thickness. Tool use for making hinges fall under this category.
Whenever Curling is done the tubular profile will not resemble a true circle .To achieve a rare circular profile a tilting operation is done prior to commencement of the curling operation. Tilting is an operation in which the edge of the component is tilted slightly to required radius of the curling diameter so that during curling it acts as flow guide.
FLANGING:-
Many sheet metal assembly components require threaded holes so that they can be fastened with the other elements of assembly. If sheet thickness is less it will not be possible to have sufficient number of threads.
Flanging or collar drawing is a operation in which a collar is formed so that more number of threads can be provided. The collar wall can also be used as rivet when two sheets are to be fastened together.
Describe the flanging operation?
Flanging or collar drawing operation in which a collar is formed so that more number of threads can be provided. The collar wall can also be used as rivet when two sheets are to be fastened together.
CALCULATION
d 1= diameter of the pierce hole
d2= core diameter of the thread
d3= size of the thread
h= height of the collar
Diameter of the pierced hole is = .45X d2
d4 = d2+ 1.35
h = 0.5d2+ s
Flanging or collar drawing operation in which a collar is formed so that more number of threads can be provided. The collar wall can also be used as rivet when two sheets are to be fastened together.
CALCULATION
d 1= diameter of the pierce hole
d2= core diameter of the thread
d3= size of the thread
h= height of the collar
Diameter of the pierced hole is = .45X d2
d4 = d2+ 1.35
h = 0.5d2+ s
PLANISHING:-
Certain parts of clocks electronic equipment and cameras require absolute flatness.
In such occasions an operation called plaiting is employed. Plaiting is an operation in which fine impressions arranged in symmetric pattern are induced on the face of the component. The inducement of the impressions are done on one face, in case where the thickness of the component is less (03. to 0.6) but for the thicker component the impression can be made on either sides.
Usually the plaiting tool comprises of two parts. A die and punch. On the die face fine serration in the form of diamond shape are milled. The depth of each serration will not be more than 0.2 mm and is provided on the die and the punch is a flat steel piece without any impressions. Both the die and punch are hardened and tempered.
The effect of plaiting is that when impression penetrates into the component face, breaks the fibers into short length, thus inducing a permanent set to the component
COMMENTS