| 摘要 |
A fluid-powered percussion tool includes a percussion piston which, under the effect of a control alternately performs a working stroke and a return stroke with the aid of a control valve. The control valve assumes a working stroke or a return stroke position, depending on the position of the percussion piston. In the working stroke position, the percussion piston is admitted with working pressure such that it performs a working stroke counter to the effect of a continuous reset force. In contrast, the percussion piston is connected in the return stroke position to a discharge line so that it performs a return stroke under the effect of the reset force. The control valve is admitted during the working stroke with working pressure and is thereby held in the working stroke position. With the approach of the percussion piston to the point of impact, the connection to the pressure line under working pressure is interrupted and only a low pressure level is maintained in the region of control valve, under the effect of which the control valve is switched to the return stroke position and kept in this position during the return stroke.
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