| 摘要 |
The invention concerns a hydraulic piston and cylinder unit fitted with a position sensor (5) designed to detect the position of the piston. In order to make this possible with cylinders with walls made of steel, i.e. a magnetically screening material, the invention calls for a magnetic conductor (9, 10) to be mounted on the outside of the cylinder wall (2). This magnetic conductor comprises a yoke (10) joined to the cylinder wall (2) at each end by a magnet (7, 8) and approximately in the middle by a central bridge (9), leaving an air gap between the yoke and the bridge. Fitted in the air gap is a magnetic-field sensor (11). The poles of the two magnets are disposed in such a way that the magnetic flux in the central bridge (9), and hence in the magnetic-field sensor (11), is zero when the piston (3), which is made of a magnetically conducting material, is in a given position. |
