Patent ID: 9234817
Filing Date: 2016-01-12
CPC Classification: G01F,G01M

Claim Text:
1. A flow rate measuring apparatus that is inserted into a through hole formed in a pipe from the outside of the pipe and is placed in the pipe such that the insertion direction into the through hole is generally perpendicular to the mainstream direction of fluid to be measured passing through the pipe, the apparatus comprising: a bypass passage, having a rectangular passage cross section, for causing part of fluid to be measured to pass therethrough; and a flat plate-shaped flow rate detecting device provided in the bypass passage, wherein the bypass passage includes: an inlet that is open in the direction toward the upstream side of the mainstream direction and takes in part of fluid to be measured; a first passage part that extends from the inlet to a first bending part along the mainstream direction; a second passage part that extends from the first bending part toward the anti-insertion direction to a second bending part along the direction perpendicular to the mainstream direction; and a third passage part that extends from the second bending part to a third bending part along the mainstream direction, the flow rate detecting device being placed such that one wall surface of the third passage part is flush with one principal surface of the flow rate detecting device, a first step-shaped part having a plurality of step shapes each consisting of two faces including a face generally perpendicular to the mainstream direction is placed on the inner wall surface on the outer circumference side of the first bending part; and a second step-shaped part having a plurality of step shapes each consisting of two faces including a face generally perpendicular to the anti-insertion direction is placed on the inner wall surface on the outer circumference side of the second bending part, and a plate-like member that divides the passage cross section of the bypass passage into the insertion direction side and the anti-insertion direction side is placed from the inlet to the downstream-side end of the second passage part along the shape of the bypass passage.