| 摘要 |
The invention is directed towards a synchronous control system in pushing and slide-bar cylinders for underground support systems. The pushing cylinders have in their piston rod a metering chamber in which a metering piston works which is supported on the cylinder base and during the retraction of the pushing cylinder pushes the pressure fluid out of the metering chamber into a metering space of the allocated slide-bar cylinder. Guided in the metering space of the slide-bar cylinder is a plunger which is fastened to the cylinder base. The synchronous control system has a control valve allocated to the pushing cylinder and intended for retracting and extending the pushing cylinder, and furthermore a manipulating valve which can be activated hydraulically and the control line of which is connected to the metering system, and an activating valve which can be activated hydraulically. Via the manipulating valve controlled by the metering system, the slide-bar cylinder is extended in synchronism with the retracting pushing cylinder, in the course of which the same lengths of stroke can be achieved. During the extension of the pushing cylinder, the annular spaces of the pushing cylinder and of the slide-bar cylinder are connected via the activating valve so that the pressure fluid pushed out of the annular space of the pushing cylinder is forced into the annular space of the slide-bar cylinder and thus the slide-bar cylinder is retracted in synchronism and with the same stroke.
|
