Percussion device for a hydraulic rock drilling machine, operating method of a percussion device and hydraulic rock drilling machine that includes a percussion device

摘要

Percussion device for a hydraulic rock drilling machine (1), the percussion device including a cylinder (4) and, inside the cylinder (4), a reciprocating movable impact piston (3), which is provided with a projection part (12) for cooperation with a braking recess (11) within the cylinder (4) for the establishment of a braking chamber in advanced positions of the impact piston with respect to a normal impact position, as seen in the impact direction (R) of the percussion device, in which a throttle slit (17) is located between wall portions of the shoulder portion (12) and the braking recess (11), and in which the percussion device includes a piston guide device (6) which is located in front of the braking recess (11) as viewed in the impact direction (R), in which a pressure channel (14), which is connected to a source of pressure medium, it is arranged to flow into the ci cylinder (4) between the piston guide device (6) and a position of the projection part (12) in a more advanced position of the impact piston (3), characterized in that the pressure channel (14) is arranged to open into an equalization chamber (13) that is arranged between the braking recess (11) and the piston guide device (6), in which a throttle slit (16) that acts against the impact piston ( 3) is formed between the braking recess (11) and the equalization chamber (13).