Sorry, your combination is currently not available. Activate your e-mail service!
What is a Counterblow Hammer?
Counter blow hammers are majorly used for forming large and ultra large forgings. The counterblow hammer is another variation of the power-drop hammer, which is widely used in Europe. The major advantage of counter blow hammers is that they operate at very high speeds but with less vibration transmitted to the foundation. These hammers develop striking force by the movement of two rams which are simultaneously approaching from opposite directions and meeting at a midway point. Some hammers are pneumatically or hydraulically actuated while others incorporate a mechanical hydraulic or a mechanical pneumatic system.
Construction and Working of a Counterblow Hammer
The basic components of a counter blow hammer are: Drive (hydraulic, pneumatic etc.), Upper Ram, Upper die, Hammer frame, Lower die, Lower ram and Hydraulic ram clutch. In a vertical counter blow hammer with a steam-hydraulic actuating system, steam is admitted to the upper cylinder and drives the upper ram downward. At the same time, pistons connected to the upper ram act through a hydraulic linkage in forcing the lower ram upward. Retraction speed is increased by steam (or air) pressure acting upward on the piston. Through proper design relative to weights (including tooling and work piece) and hydraulics (slower lower-assembly velocities), the kinetic energy of the upper and lower assemblies can be balanced at the impact. Horizontal counter blow hammers have two opposing, die-carrying rams that are moved horizontally by compressed air. Heated stock is positioned automatically at each die impression by a preset pattern of accurately timed movements of a stock handling device. A 90° rotation of stock can be programmed between the blows.
Counterblow Hammer and its Advantages
The rams of a counter blow hammer are capable of striking repeated blows and they develop combined velocities of 5 to 6 m/s (6 to 20 ft/s). Compared to single action hammers, the vibration of impact is reduced, and approximately the full energy of each blow is delivered to the work piece, without loss to an anvil. As a result, the wear of moving hammer parts is minimized, contributing to longer operating life of the machine. At the time of impact, forces are cancelled out, and hence no energy is lost to the foundation. In fact, counterblow hammers do not require the large inertia blocks and foundations needed for conventional power drop hammers which involve comparatively high intense vibrations.