| 摘要 |
PURPOSE:To perform rotation detection and flow rate detection with high reliability by inserting a magnetic body of triple structure into a nonmetallic material and using this nonmagnetic material for a rotating body which has magnetism and rotates by the flow of fluid in a flow passage. CONSTITUTION:When the fluid flows from an entrance 6 to an exit 7, it is made into an axial swivel flow by a fixed vane 8 and the rotating body 9 is rotated by the swivel flow. The rotational frequency of the body is proportional to the flow rate, and the rotational frequency is detected by a magneto-resistance element 11 and processed by a control circuit 14 to calculate the flow rate. A ferromagnetic surface treatment 16e for forming a magnetic body and a corrosion treatment 17 are carried out on the core bead 15 made of a lightweight resin material as to the rotating body 9, and the external part is made of a resin molding 8. |
