摘要:
A percussion device for a hydraulic rock drilling machine (1) including, inside a cylinder (4), a to and fro moveable impact piston (3), which is provided with a land portion (12) for cooperation with a braking recess (11) in the cylinder (4) for the establishment of a braking chamber in advanced positions of the impact piston, wherein a throttle slit (17) is arranged to be established between the land portion (12) and the braking recess (11). A pressure channel (14), being connected to a pressure medium source, is arranged to debouch in the cylinder (4) between the piston guiding device (6) and a position of the land portion (12) in a most advanced position of the impact piston (3). The invention also concerns a method and a hydraulic rock drilling machine.
摘要:
A device in a hydraulic rock drilling machine (1) has a distribution valve (7, 7′, 7″) for controlling hydraulic flow to different parts of the rock drilling machine. The distribution valve has a valve body (8, 8′, 8″) which moves to and from in an axial direction inside a valve chamber (33). The valve chamber is limited in axial direction by two valve end walls (10, 11; 10′, 11′; 10″, 11″). One of the valve end walls is movable in an axial direction against an abutment (12, 12″) to define an end position for the valve body, and a pressing device (13, 13′, 13″) is provided for pressing at least one of the valve end walls against the abutment. A rock drilling machine includes the device.