Hydraulic Hammering Device

A hydraulic hammering device comprising:

• a transmission member configured to transmit a propulsive force toward a crushing target side to a tool;
• a hammering mechanism configured to strike a blow on a rear portion of the transmission member;
• a pushing piston disposed immediately behind the transmission member, the pushing piston having a smaller propulsive force than a propulsive force of a device main body of the hydraulic hammering device;
• a damping piston positioned behind the pushing piston and disposed to slide reciprocally against the pushing piston in forward and backward directions, the damping piston having a greater propulsive force than the propulsive force of the device main body of the hydraulic hammering device;
• a pushing chamber configured to generate a propulsive force in the pushing piston;
• a damping chamber configured to generate a propulsive force in the damping piston;
• a damper pressure source configured to supply the pushing chamber and the damping chamber with hydraulic fluid by way of a high-pressure circuit;
• a drain circuit provided in constant isolation from the pushing chamber and the damping chamber and configured to discharge a leakage of hydraulic fluid from a location of sliding contact between the pushing piston and the damping piston to a tank;
• a first throttle interposed in the drain circuit;
• a pushing passage connecting the pushing chamber and the high-pressure circuit;
• and
• a damping passage connecting the damping chamber and the high-pressure circuit, wherein
• in a supply path of hydraulic fluid including the high-pressure circuit and the pushing passage, only a check valve configured to, while allowing supply of hydraulic fluid from the damper pressure source to the pushing chamber, restrict an outflow of hydraulic fluid from the pushing chamber to the damper pressure source is provided, and
• in a supply path of hydraulic fluid including the high-pressure circuit and the damping passage, only a second throttle is provided.