Press Forging: In press forging, impression dies are used in which partd are made by plastically deforming a metal blank into die avities by slow squeezing action. The forging pressure builds up from the start to the end of stroke, resulting in maximum penetration and in improved grain flow throughout the entire forging . completed forgings are ejected manually or mechanically from die-cavities.
The power flow diagram of a crank type mechanical press is as shown in fig.An electric motor is drives the flywheel mounted on the counter shaft by means of a belt drive. Torque from the counter shaft is transmitted to the crank shaft through gearing. From the crank shaft, reciprocating motion is given to the ram with the help of connecting rod. The bottom die is locked in position by means of wedge mechanism. Disc clutch is used to start and stop motion of ram which is brought to the gradual stop by means of brakes. Mechanical presses are faster than hydraulic presses and operate at about 25 to 100 stroke per minute. Their capacities range from 900 KN to 110 MN and they are generally employed for non-ferrous alloys weighting from upto about 135 N.