Egr cooler

Abstract

Coolant water is prevented from stagnating with no restriction to a mounted posture of an EGR cooler to a vehicle. The EGR cooler has tubes 3 and a shell 1 surrounding the tubes 3 , coolant water 9 being fed into and discharged from the shell 1 , exhaust gas being passed through the tubes 3 for heat exchange of the exhaust gas with the coolant water 9 . An annular coolant-water supply chamber 11 is fitted over the shell 1 near an axial end of the shell 1 . A coolant-water inlet pipe 4 is connected to a periphery of the supply chamber 11 . Communicating holes 12 are formed at a plurality of peripheral positions sequentially along a portion of the shell 1 surrounded by the supply chamber 11 such that the holes have gradually reduced diameters as they are apart from the connection of the shell with the inlet pipe 4 , so that the coolant water 9 may be introduced into the shell 1 substantially evenly through the communicating holes 12.

1 . An EGR cooler with tubes and a shell surrounding said tubes, coolant water being fed into and discharged from the shell, exhaust gas being passed through said tubes for heat exchange of said exhaust gas with said coolant water, the EGR cooler comprising an annular coolant-water supply chamber fitted over said shell near an axial end of the shell, a coolant-water inlet pipe connected to a periphery of the supply chamber, communicating holes formed at a plurality of peripheral positions on a portion of the shell surrounded by said supply chamber such that said holes have gradually reduced diameters as said holes are peripherally apart from the connection between the chamber and the inlet pipe so as to substantially evenly introduce the coolant water into the shell via the holes.  
   
   
       2 . The EGR cooler according to  claim 1 , wherein the portion of the shell surrounded by the supply chamber has a required extent of peripheral zone facing the inlet pipe and having no communicating holes.