| 摘要 |
PURPOSE:To obtain a compact flow rate detector with a simple construction, by molding the outer circumference of impeller located inside the tube of nonmagnetic material with a plastic magnet in a body by double-molding and by detecting the magnetic field of the magnet with the use of Hall element. CONSTITUTION:Marginal section of rectifier tubes 5 and 5 which provide plastic bearings 6 and 6, and rectifier holes 7 and 7 are kept on the inner wall of a cylinder type body 1 made of nonmagnetic material such as plastics. Shafts 11, 11 of a plastic impeller 10 whose center circumference portion is double-molded by a plastic magnet 12 are inserted into the bearings 6, 6 of the rectifier plates 5, 5. Magnetic field of a magnet 12 is detected by a Hall effect element 13 located on the body 1. As it is constructed as described above, when fluid is flown in a channel 8 in the direction described with an arrow mark, the impeller 10 is started to turn and the magnet 12 gives intermittent magnetic field proportion to the flow rate to the Hall effect element 13. Then, the flow rate can be obtained by measuring the pulses which generate Hall effect element. |
