| 摘要 |
PURPOSE:To have precision stroke position sensing continuously by forming a differential type transformer from a free piston consisting of magnetic substance and a primary and a secondary coil furnished around an oil sump, and using the output of the differential transformer as index for the stroke position. CONSTITUTION:If a piston 3 slides in a damper cylinder 1 for ex. toward the compression side, the working oil moves from an oil chamber 5 to another 4 and also flows into an oil sump 11 via a hollow 8 in a piston rod 2, to cause a free piston 12 to be lifted against the oppositely acting force of the air in an air chamber 13 and a return spring 15. Now AC current flows in a secondary coil 17 furnished around said oil sump 11 according to the amount of displacement of said free piston 12, and a controller performs conversion of damper stroke on the basis of output voltage proportional to said displacement. That is, the stroke position of damper is sensed continuously by a differential type transformer composed of free piston 12 and the primary and secondary coils 16, 17. |
