Why are hot forging presses so big?

Why are hot forging presses so big?

The reason why hot forging machines are "big" is not simply for the sake of being "big", but the result of the hot forging process, material properties, deformation force requirements and automation support. It can be broken down into five core reasons:

1. Huge deformation force

Although the metal becomes soft after heating, hot forging is usually carried out at 900–1200 °C, at which time the material still has a fairly high flow stress. Taking a 50 mm diameter and 200 mm long 42CrMo connecting rod as an example, the final forging force can reach 3000–5000 kN. Large flanges, bucket teeth, wheel hubs and other parts have a larger projected area, and the required tonnage is often more than 10,000 kN (1,000 tons). The equipment frame must be made heavy and thick to resist elastic deformation.

2. Energy-inertia dual reserve

Mechanical hot forging presses rely on flywheel-clutch to release energy instantly. The flywheel diameter is often 2-4 m and the mass is more than ten tons; hydraulic hot forging presses require large-flow pump stations and high-pressure accumulators. These "giant accumulators" determine the overall dimensions of the machine.

3. High rigidity and high guidance requirements

In order to obtain forging accuracy of ±0.1-0.2 mm, the frame rigidity must reach the kN/μm level, and the slide guide length is usually ≥ 1.2 times the slide stroke, so the bed, guide rails, and connecting rods are all enlarged to form a "short and fat" body.

4. Integration of mold and heating system

The mold needs water cooling, ejection device, and fast mold change mechanism inside; the outside is also equipped with a 1200 °C walking beam heating furnace, manipulator, and spray graphite lubrication station. The entire set of peripheral equipment is "hung" around the main machine, making the production line occupy hundreds of square meters, which looks "huge" visually.

5. Large-sized parts determine "large molds, large tables, and large strokes"

For example, a 14,000-ton double-crank hot die forging press is specially used to forge 250 kg heavy crankshafts. The slide stroke is 600 mm, the table is 3.5 m×2.2 m, and the main machine weighs 1,600 tons and is 12 m high. This is a direct result of the size of the parts.

What products can hot stamping machines produce?

1. Automotive industry

Engine parts: connecting rods, crankshafts, camshafts, piston pins

Transmission system: gears, synchronizer rings, universal joint forks, drive shaft flanges

Chassis system: steering knuckles, control arms, wheel hub bearing seats, suspension brackets

2. Aerospace

Turbine blades, landing gear parts Fasteners: bolts, rivets

3. Engineering machinery

Hydraulic components: valve bodies, pump housings

Track parts: track shoes, supporting wheel axles Heavy gears

4. Energy industry

Oil drilling: drill bit joints, high-pressure valve bodies

Wind power: gearbox planetary gears, wheel hubs

5. Hardware tools

Wrenches, pliers, hammers, axes

6. Rail transit

High-speed rail axles, brake systems: brake discs, hook tail frames

7. Agricultural machinery

Plowshares, rake blades, harvester blades