| 摘要 |
<p>In a positioning device for a piston cylinder aggregate (1) with a piston rod (5) being connected to the piston, said piston rod at determined axial positions comprising magnetic bodies, a sensor (10) for sensing the magnetic field of the magnetic bodies is positioned adjacent the piston rod (5). The magnetic bodies are comprised of plate shaped permanent magnet (8) with essentially circular cylindric envelope surface. Each magnet (8) is arranged with its magnetic axis essentially coaxial to the axis of the piston rod (5) and with its magnetic poles arranged in the opposite direction with respect to the poles of adjacent magnets. Finally the piston rod comprises an essentially smooth, pipe shaped outer covering (6) of a non magnetic material, which encloses the magnets (8) but allows passage of magnetic flux.</p> |
