PROBLEM TO BE SOLVED: To provide a gas flow indicator having a structure that has no directionality when in use, that can reliably confirm a gas flow when a flow rate is low and can suppress vibration sound when the flow rate is high.SOLUTION: A gas flow indicator includes: a cylinder 11 whose inside can be visually recognized from outside a piston 12 movably inserted into the cylinder an upstream member 13 provided upstream of the cylinder a downstream member 14 provided downstream of the cylinder and a spring member 15 that presses the piston in an upstream direction of the cylinder. On an inner circumferential face of the cylinder in a range from an intermediate part to a downstream end of the cylinder in an axial direction, a plurality of inclined grooves 16 each having an inclined bottom face 16a whose depth gradually increases toward the downstream end, and a plurality of guide faces 17 having the same inner diameter as the inner circumferential face of the cylinder are further provided between the inclined grooves adjoining each other in a circumferential direction.SELECTED DRAWING: Figure 1COPYRIGHT: (C)2016,JPO&INPIT【課題】使用時の方向性がなく、低流量時のガス流の確認を確実に行えるとともに、高流量時の振動音の発生を抑えることができる構造を備えたガス流表示器を提供する。【解決手段】外部から内部を視認可能なシリンダ11と、シリンダ内に移動可能に挿入されたピストン12と、シリンダの上流側に設けられる上流側部材13と、シリンダの下流側に設けられる下流側部材14と、ピストンをシリンダの上流側に付勢するバネ部材15とを備えたガス流表示器であって、シリンダのシリンダ軸線方向中間部から下流側端部にわたる範囲の内周面に、下流側端部に向かって次第に溝の深さが深くなる傾斜底面16aを有する複数の傾斜溝16を設けるとともに、周方向に隣接する傾斜溝同士の間に、シリンダの上流側内周面と同一内径を有する複数のガイド面17を設ける。【選択図】図1
