| 摘要 |
PURPOSE:To prevent the propagation of impact waves to oil-pressure motor when an oil-pressure hammer drops by a method in which an oil-pressure cylinder for driving the oil-pressure hammer and the return path of an oil-pressure motor driving an auger are mutually connected and a shuttle valve is provided to the return path. CONSTITUTION:Switch valves 5 and 6 are provided to pipelines through which oil is supplied from an oil pressure source P to an oil-pressure cylinder 1 driving an oil-pressure hammer and an oil-pressure motor 2 driving an oil-pressure auger. Also, the return paths 12 and 13 for the oil-pressure motor 2 and the oil- pressure cylinder 1 are mutually connected, and a shuttle valve 14 to prevent the propagation of pressure waves is provided between the oil-pressure cylinder 1 and the oil-pressure motor 2. Thus, the propagation of high surge pressures generated when the oil-pressure hammer drops to the oil-pressure motor 2 can be prevented and the maloperation of the oil-pressure auger can also be prevented. |
