| 摘要 |
<p>Hydraulic tilting device for tilting a cab of a vehicle between a driving position and a tilted position. The tilting device has a double-action hydraulic tilting cylinder (5) for tilting the cab, having a piston/piston rod assembly (8, 9) which forms in the cylinder space (7) a pull chamber (12), which, when hydraulic fluid is fed to it, draws in the piston/piston rod assembly, and a push chamber (13), which, when hydraulic fluid is fed to it, pushes out the piston/piston rod assembly. In addition, a lost-motion duct (30) is present in the ports (31, 32) emerging in the cylinder space, which lost-motion duct interconnects the pull chamber (12) and the push chamber (10) in a lost-motion mode of the tilting device. A hydraulically operated lost-motion valve (40) has a slide body, which is displaceable between a closed position, in which the first (42) and second (43) valve ports are closed off from each other, and an open position, in which the first (42) and second (43) valve port are interconnected. The lost-motion valve is provided with a spring means (48), which pressurizes the slide body in the direction of the closed position thereof. The closing-control surface of the lost-motion valve (53) processes an OR-valve having a first (53a) and a second (53b) inlet port, which are respectively connected to the cylinder space (12) and to a line (55) extending between the push terminal (15) of the tilting cylinder and a pressure port (4) of the pump (2). The outlet port (53c) is connected to the closing-control surface (51) of the lost-motion valve (40).</p> |
