An air cooling device includes a first inlet surge tank, a first heat exchanger to cool air introduced from the first surge tank, a second inlet surge tank, a second heat exchanger to cool air introduced from the second surge tank, and an outlet surge tank. The outlet surge tank receives both of airs introduced from the first heat exchanger and the second heat exchanger and the airs flows from the outlet surge tank toward an internal combustion engine. The outlet surge tank includes a merging space and a fixing hole. The merging space is where the airs introduced from the first heat exchanger and the second heat exchanger merge with each other. A fastening member to fasten the outlet surge tank passes through the fixing hole from an outer surface of the outlet surge tank away from the merging space toward the internal combustion engine.