a group of machines for pressure shaping of metals (forging and stamping). The main types of forging machines are horizontal, vertical, and rotary machines and forging rolls.
Horizontal forging machines, which have horizontal movement of the working member, are designed for hot flashless die forging of bar-stock. The working member is rigidly connected to a crank gear mechanism, and the auxiliary parts are actuated by a camshaft mechanism. In contrast to the horizontal forging machines and other crank gear machines, the driveshaft of the vertical and rotary forging machines is not connected rigidly to the slide to which the working tool is attached. Vertical forging machines, in which the working tool moves vertically, are designed for the production of small forgings, such as blanks for knives, hooks, and chisels (with single heating), and larger articles, such as blanks for propellers, axes, and other articles requiring repeated heating during the manufacturing process. These machines perform sequentially the basic forging operations— drawing, swaging, and rolling.
A special design feature of vertical forging machines is the transmission of rotation from an eccentric shaft to the slide through an intermediate part (crank). The slide is constantly pressed against the crank by springs, whose force is overcome during operation of the machine and under whose influence the slide returns to the starting position after completion of the working cycle. The machines may have up to six slides and can produce up to 800 impacts per minute.
Rotary forging machines, in which the working element rotates together with the tool, are designed for swaging and hot drawing of articles, which usually have the shape of bodies of rotation. The intermediate part that transmits the motion from the driveshaft to the slide is a cylindrical yoke with rolls mounted on its outer surface and a spindle with radial slots inside it. The slides and dies are located within the slots of the spindle. Rotary forging machines may have fixed yokes and rotating spindles or fixed spindles and rotating yokes. With the spindle or yoke rotating at 500 rpm, machines with ten rolls can produce up to 2,500 impacts per minute (a crank gear automatic press performs up to 700 cycles per minute).
Forging rolls occupy an intermediate position between forging machines and rolling units; they make possible an increase in productivity by a factor of 10 as compared to die-stamping machines.
Horizontal forging machines are widely used because of their very high productivity and versatility, which make possible the production of a variety of forgings of complex configuration with high dimensional precision and surface smoothness.
REFERENCESDin, I. M. Izgotovlenie pokovok na spetsial’nykh mashinakh. Moscow-Leningrad, 1958.
Zalesskii, V. I. Oborudovanie kuznechno-pressovykh tsekhov. Moscow, 1964.
V. P. LINTS