Heat exchanger and corresponding manufacturing method

Abstract

A heat exchanger for an exhaust gas recirculation system includes an exchanger body delimiting an inner volume, and longitudinal tubes housed in the inner volume and forming a layer of tubes fitting between upper and lower planes. The tubes are separated by passages for circulating a second fluid, the upper plane being across from an upper part of the exchanger body. A second fluid inlet is arranged in the upper part of the exchanger body; and a member guides the second fluid in the inner volume. A deflector at least partially closes off the interstitial space between the upper part and the upper plane.

1 . A heat exchanger for an exhaust gas recirculation system, comprising:
 an exchanger body delimiting an inner volume;   a plurality of longitudinal tubes housed in the inner volume and provided to circulate a first fluid, at least some of the longitudinal tubes being transversely juxtaposed and forming a layer of longitudinal tubes fitting between upper and lower planes, the longitudinal tubes of said layer of longitudinal tubes being separated from one another by passages for circulating a second fluid, at least the upper plane including longitudinal and transverse directions, the upper plane being directly across from an upper part of the exchanger body and being separated from the exchanger body by an interstitial space;   a second fluid inlet opening out into the inner volume and arranged in the upper part of the exchanger body; and   a guide member to guide the second fluid in the inner volume, and including a deflector having a transverse zone at least partially closing off the interstitial space between the upper part and the upper plane.   
     
     
         2 . The heat exchanger according to  claim 1 , wherein the guide member comprises a grid that distributes the second fluid, the grid being arranged in the interstitial space between the upper part and the upper plane, across from the second fluid inlet. 
     
     
         3 . The heat exchanger according to  claim 2 , wherein the distribution grid extends over substantially an entire width of the layer of longitudinal tubes and has, across from each passage, at least one hole, the second fluid inlet being placed across from at least one central passage from among the passages, the at least one hole having a passage section increasing transversely from the at least one central passage. 
     
     
         4 . The heat exchanger according to  claim 2 , wherein the deflector of the guide member comprises teeth engaged in the passages. 
     
     
         5 . The heat exchanger according to  claim 4 , wherein the distribution grid, the transverse zone, and the teeth are integral with one another. 
     
     
         6 . The heat exchanger according to  claim 4 , wherein the distribution grid, the transverse zone, and the teeth are formed in a same metal plate. 
     
     
         7 . The heat exchanger according to  claim 4 , wherein each tooth extends transversely over an entire width of the corresponding passage. 
     
     
         8 . The heat exchanger according to  claim 4 , wherein each passage extends over a determined height along an elevation direction substantially perpendicular to the longitudinal and transverse directions, the corresponding tooth extending over a height comprised between 5% and 50% of said determined height. 
     
     
         9 . The heat exchanger according to  claim 8 , wherein at least one of two longitudinal tubes surrounding said passage has a rib protruding in the passage, extending the tooth in the elevation direction, the rib preferably having interruptions. 
     
     
         10 . A method for manufacturing a heat exchanger according to  claim 1 , the manufacturing method comprising the following steps:
 Forming the guide member that guides the second fluid, by cutting and shaping a metal plate;   Placing the longitudinal tubes and the guide member in the exchanger body; and   Fastening the longitudinal tubes, the guide member, and the exchanger body together.