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 a portion of 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 a portion of 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 be supplied with hydraulic fluid from a fluid supply source to provide the pushing piston with the smaller propulsive force;
• a damping chamber configured to be supplied with hydraulic fluid from the fluid supply source to provide the damping piston with the greater propulsive force;
• a drain circuit 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, the drain circuit being separated from the damping chamber and the pushing chamber by sliding contact between the device main body and the damping piston;
• a direction-restrictor provided in a high-pressure circuit between the damping chamber and the pushing chamber, and the fluid supply source, the direction-restrictor being configured to restrict an outflow of hydraulic fluid from a side of the direction-restrictor relative to the damping chamber and the pushing chamber to a side of the direction-restrictor relative to the fluid supply source, while allowing an inflow of hydraulic fluid from the side of the direction-restrictor relative to the fluid supply source to the side of the direction-restrictor relative to the damping chamber and the pushing chamber;
• and
• a throttle provided in the drain circuit.