Magnet mounting structure and mounting method for magnetic sensor of crank mechanism in membrane gas meter

摘要

PROBLEM TO BE SOLVED: To provide a structure capable of easily and surely fitting a magnet for magnetic sensor.SOLUTION: A magnet fitting structure for magnetic sensor of a crank mechanism in a diaphragm gas meter is subjected. The magnet fitting structure for magnetic sensor comprises: a crank mechanism 4 in which a metallic upper-stage crankpin 45 is fitted to an upper-stage crank arm 44; a magnet pedestal 5 fitted to the upper-stage crankpin 45; and a magnet for magnetic senor fitted to the magnet pedestal 5. A rotation speed of the rotating magnet is detected via a magnetic sensor, and a gas flow rate is measured. The magnet pedestal 5 includes a metal plate part 51 made of a metal and a resin plate part 55 made of a synthetic resin, and the upper-stage crankpin 45 is fitted while being inserted into a pin fitting hole 52 of the metal plate part 51. The magnet is fitted to the resin plate part 5 via magnet fitting means.SELECTED DRAWING: Figure 3A