| 摘要 |
One purpose of the present invention is to provide an inner fin for the tube of an EGR cooler, wherein heat exchange between exhaust gas and cooling water is promoted, a drop in performance due to soot clogging is prevented, and assembly during production is facilitated. An inner fin (1) which is installed within an EGR cooler for cooling exhaust gas and is used in a flat tube for passing the exhaust gas, wherein: a plate material is formed in a shape in which concaves and convexes are repeatedly formed in the width direction and in an off-set shape in which said repetition is alternately offset in the right and left in the gas flow direction at every predetermined length; and a first protrusion (11) tilted toward the upstream of the gas flow direction and a second protrusion (12) disposed downstream the first protrusion (11) and tilted toward the downstream of the gas flow direction at the same angle as the tilt angle of the first protrusion (11) are formed by cutting and raising a top surface part or a bottom surface part for each segment (10) surrounded by a pair of right and left side walls. |
