Abstract: A gas-liquid separation mechanism of a reserve tank for separating gas bubbles contained in a coolant flowing into a reserve tank provided in a circulation path of the coolant includes: an inlet opening for the coolant provided on a first side wall of the reserve tank; an outlet opening for the coolant provided on a second side wall opposite to the first side wall; a bubble emission port that is provided on an upper wall of the reserve tank and emits the bubbles separated from the coolant; a flow adjuster that adjusts a flow of the coolant having flowed in from the inlet opening and makes the flow rise and flow backward; and a first small wall that is provided in a vicinity of the bubble emission port and downstream of the bubble emission port in a direction where the flow flows backward, and protrudes downward from the upper wall.

Abstract: A gas-liquid separation mechanism of a reserve tank for separating gas bubbles in a coolant flowing into a reserve tank provided upstream of a liquid pump in a circulation path of the coolant includes: an inlet opening for the coolant provided at a lower portion of one of opposing side walls; an outlet opening for the coolant provided at a lower portion of the other side wall; a bubble emission port provided on an upper wall and configured to emit the gas bubbles separated from the coolant; and a partition wall extending substantially parallel to a direction from the inlet opening to the outlet opening and vertically dividing the reserve tank into first and second chambers. The partition wall includes a downstream communicating hole below an end portion proximate to the outlet opening and an upstream communicating and an upstream communicating hole above an end portion proximate to the inlet opening.