PILE-DRIVING HAMMER Russian patent published in 2007 - IPC E02D7/10 

FIELD: construction equipment, particularly adapted to drive all type of piles in ground and to remove piles from ground, as well as for ground ramming.

SUBSTANCE: pile-driving hammer comprises piston hydropneumatic accumulator, hydraylic distributor with hydraulic control chambers created at ends thereof, channels, delivery and discharge pipelines and vertical power cylinder fixedly connected to head. Mating inner power cylinder surface are striker and two-stage piston arranged under the striker. The two-stage piston intermittently contact with lower striker end by end of stage having lesser diameter, wherein during said contact striker is in its lower position. The two-stage piston, power cylinder and striker define two isolated cavities. Upper cavity is permanently communicated with atmosphere through check valve. Central cavity is connected to delivery pipeline and accumulator. Lower cavity arranged under two-stage piston stage having larger diameter is filled with working liquid and is communicated with discharge line through hydraulic distributor. Control chamber having lesser area is permanently communicated with delivery pipeline. Control chamber having greater area is alternately connected with delivery and with discharge pipeline through control means. Control means is made as two-stage plunger sliding in axial direction. Plunger stage having greater diameter is permanently inserted in cavity communicated with delivery pipeline. Another end thereof is located in annular cavity connected to discharge means. Plunger stage having smaller diameter has free end touching end piston surface facing hydraulic cavity of hydropneumatic accumulator.

EFFECT: increased reliability and performance.

3 cl, 1 dwg