| 摘要 |
<P>PROBLEM TO BE SOLVED: To provide an EGR cooler favorably adapted to a diesel engine without largely deteriorating performance of the engine. <P>SOLUTION: This EGR cooler comprises a tube 3 and a shell wrapping the tube 3. Cooling water is fed into/discharged from inside of the shell 1, and exhaust gas 10 is guided from the diesel engine into the tube 3 for heat exchange between the exhaust gas 10 and the cooling water 9. Spiral protrusions 12, 13 having inclination θ of 26-50° for a surface crossing the shaft center line x of the tube 3 are formed on inner circumferential surface of the tube 3. <P>COPYRIGHT: (C)2004,JPO |
