Patent attributes
A flow detecting device is provided to a fluid passage through which a main flow of fluid passes. The flow detecting device includes a sensor body, a heating element, a lead portion, and a guard member. The sensor body has a bypass passage through which a bypass flow is distributed partially from the main flow. The heating element is provided in the bypass passage. The lead portion connects with the heating element via a connecting portion. The heating element generates heat by being supplied with electricity via the lead portion for detecting the bypass flow in accordance with heat radiated from the heating element. The guard member is provided to an upstream of the connecting portion with respect to the bypass flow for deflecting the bypass flow from the connecting portion.