| 摘要 |
<P>PROBLEM TO BE SOLVED: To provide an EGR cooler which can be suitably applied to a diesel engine without causing great performance drop. <P>SOLUTION: In the EGR cooler provided with a tube 3 and a shell 1 surrounding the tube 3 and performing heat exchange between exhaust gas 10 and cooling water 9 by supplying and discharging cooling water 9 to and from an inside of the shell 1 and introducing exhaust gas from a diesel engine into the tube 3, three strips of spiral shape projections 12, 13, 14 is formed on an inner circumference surface of the tune 3 in parallel with mutually shifting phase in a circumference direction, ratio P/D of pitch P of the spiral shape projections 12, 13, 14 to inner diameter D of the tube 3 is set to 2.0-4.0 and ratio H/D of height H of the spiral shape projections 12, 13, 14 to inner diameter D of the tube 3 is set to 0.1-0.2. <P>COPYRIGHT: (C)2007,JPO&INPIT |
