| 摘要 |
<p>A protection arrangement for a tool set in a hydraulic press in which press, a press ram can be moved by at least one rapid- or fast-stroke cylinder piston unit and at least one working stroke pressure unit in a working stroke direction. The protection arrangement protects the tools from an overloading by a foreign object or body situated in the tool space and includes a displacement or path switch monitoring a portion of the path of movement of the ram and a further switching element which responds during movement of the press ram, as well as a control circuit for evaluating the sequence of response of the displacement or path switch and the switching element in such a way that a fault signal is produced if the switching element responds before the path or displacement switch. The path or displacement switch responds when the tool moved by the press ram has come to a distance or almost to a distance from the other tool which corresponds to a previously given thickness of the workpiece with the switching element being constructed as a signal transmitter which is responsive to a retardation or increase in resistance in the movement of the press ram in the working stroke direction.</p> |
