Piston-cylinder arrangement of motor vehicle, has targets arranged such that the first target is moved in range of first and second loops of first secondary coil, and second target is moved past the sensor, during movement of piston

摘要

The piston-cylinder arrangement comprises a piston (15) which is slidably mounted in a cylinder in axial direction, and a sensor system for inductive displacement sensor. On the piston, at least two targets (16,17) made of metal such as aluminum, are arranged in electrically conductive material and are spaced radially and axially from each other and to the cylinder. The targets are arranged such that the first target is moved in the range of first and second loops of first secondary coil, and the second target is moved past the sensor, during movement of piston. The piston-cylinder arrangement comprises a piston which is slidably mounted in a cylinder in axial direction, and a sensor system for inductive displacement sensor. On the piston, at least two targets made of metal such as aluminum, are arranged in an electrically conductive material and are spaced radially and axially from each other and to the cylinder. The sensor is arranged in a primary coil (12) for generating magnetic field, and at least two sensors are arranged in primary coil and secondary coil for sensing target positions. The coil axes are perpendicular to the direction of movement of the piston and the secondary coils are formed with crossed coils. The first loop of the first secondary coil has a width equal to half of width of the primary coil and a length which is half the length of the primary coil. The first loop is arranged in a corner region of the primary coil surface for covering a quarter of the primary coil surface, and a second equal sized loop is arranged adjacent to the first loop in the longitudinal direction. The first and second loops are connected by cross-conductors, and in the transverse direction, a third equally large loop is arranged adjacent to the second loop and connected through cross-conductors with the second loop. A fourth large loop is arranged adjacent to the first loop in the longitudinal direction in addition to the third loop in the transverse direction. The fourth loop is connected to the third loop through cross-conductors, such that the area of the four loops covers the surface of the primary and secondary coils and the first loop has a width equal to half the width of the primary coil and a length corresponding to the length of the primary coil. A first loop is positioned within the primary coil, for covering the surface of first and second loops of the first secondary coil, and a second equally large loop is arranged in the transverse direction adjacent to the first loop. The second loop is connected to the first loop through cross-conductors, and the targets are arranged such that the first target is moved in the range of the first and second loops of the first secondary coil, and the second secondary coil is moved past the sensor, during movement of the piston.