| 摘要 |
A valve device (V, 4') for controlling the movement in a machine housing (2) of a reciprocating percussion piston (3) of a percussion device (1) for a rock drilling machine with a first chamber (5) that can be pressurized for forward driving of the percussion piston (3) and a second chamber (8) that can be pressurized for back-driving of the percussion piston (3), wherein the valve device includes a to and fro movable valve element (20), the movement of which being controlled as a response to the position of a valve portion (V) of the percussion piston in a valve housing portion by periodically pressurising a signal chamber (21) actuating the movement of the valve element over signal conduit means (22, 23, 24). Said signal conduit means includes at least two signal conduit portions (23, 24), which are arranged for essentially simultaneous pressurising through co-operation between a corresponding number of valve control edges (25, 26) on the valve portion of the percussion piston and edges (34, 35) or control chambers in the machine housing. The invention also concerns a percussion device and a rock drilling machine.
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