Testing of Hydraulic Hammering Tool with Restrictive Control of Energy and Frequency of Blows

The article reports testing results of a hydraulic hammering tool with independently controllable energy and frequency of blows. The blow frequency is adjustable via the fluid flow rate, and the blow energy—via the pressure at the onset of a working cycle. The hydraulic hammering tool and its performance measurement procedures are described, including the pre-blow velocity—using an original piston position sensor composed of two pairs of light-emitting and photo diodes arranged in front of the collision plane of the piston and the breaking tool. The approach allows changing the blow frequency of the tool by 4 times, its blow energy by 5 times and the impact power by 20 times. The authors present the experimental oscillograms of the dynamic characteristics of working cycles and the experimental curves of the integral output characteristics, cycle start pressure, and fluid flow rate. An experimental-and-analytical estimation method is developed for the pre-blow piston velocity using the theorem of a kinetic energy of a material point.