Demolition Shears

High-speed valves for scrap and demolition shears connect the cylinder rod side directly to the valve block while in the high-speed position. As soon as the shear comes into contact with the material, the pressure increases. Once a predefined pressure is reached, the valve spool automatically switches to the power mode by connecting the rod side to the hydraulic circuit.

In many hydraulic applications, high return line pressures cause unnecessary energy losses and can even reduce machine performance. As a result, the full force is not available at the attachment. In some cases, the pump is pushed back through the power control system, and speed losses must also be accepted. When cylinders are used in attachments, high flow rates on the rod side can quickly reach up, to twice the pump flow. Main control valves are often not designed to handle these flow rates. By providing an additional direct return-to-tank path via a 3/3 directional control valve, these losses can be significantly reduced. Reducing the return pressure by, for example, 30 bar at a flow rate of 400 l/min provides more than 20 kW of additional power at the attachment or, correspondingly, significantly reduces energy losses. The valve therefore functions as a bypass valve for the main control block.