| 摘要 |
The outer layer of concrete roadbeds and other exposed concrete surfaces erode and deteriorate, and, when being deteriorated, the outer layer must be removed and replaced by a new concrete layer. A tube (22) with a nozzle (23) at its end can be used for removing the concrete by a water jet. The tube is mounted on a carriage (20) that reciprocates along a feed beam (15). The tube is pivotable in two planes and hydraulic motors (rotary motors (21,24) and hydraulic cylinder (26)) are used for the movements of the tube and the carriage. The hydraulic motors are controlled by an electronic control unit (40) that controls distributing valves (42-44) for the hydraulic conduits (hoses) of the motors. Flow meters in the form of electric pulse transmitters (56,57,58) in the hydraulic conduits of the motors are coupled to the control unit (40). The pulse transmitters are positioned at a distance from the feed beam, and hydraulic lines but no electric lines lead to the feed beam. |
