Heat exchanger

Abstract

A heat exchanger has a core and header tanks. The core includes passage units stacked in a unit sacking direction and fins. Each passage unit includes a first passage member and a second passage member connected to each other such that a second fluid passage is provided therein. The passage units are stacked such that first fluid passages are provided between bent portions of the first and second passage members of the adjacent passage units. The fins are disposed inside of the passage units and held by the bent portions of the first and second passage members. The core has core end walls constructed of at least one of first side walls of the first passage members and second side walls of the second passage members. The header tanks are disposed at ends of the core and provide tank inner spaces with the core end walls.

1 . A heat exchanger for performing heat exchange between a first fluid and a second fluid, comprising:
 a core including passage units stacked in a unit stacking direction and fins disposed inside of the passage units,
 each passage unit including a first passage member and a second passage member coupled to each other such that a second fluid passage through which the second fluid flows is provided therein, 
 the first passage member having a first main wall and first side walls extending from a first end and a second end of the first main wall and being substantially perpendicular to the first main wall, 
 the second passage member having a second main wall and second side walls extending from a first end and a second end of the second main wall and being substantially perpendicular to the second main wall, the second main wall opposed to the first main wall in the unit stacking direction, the second side walls connected to the first side walls, 
 the first main wall having a first contacting portion and a first bent portion, the first bent portion projecting inside of the passage unit from the first contacting portion and providing a first outer space on an outer side of the passage unit, the first bent portion extending throughout from the first end to the second end of the first main wall, 
 the second main wall having a second contacting portion and a second bent portion, the second bent portion projecting inside of the passage unit from the second contacting portion and providing a second outer space on an outer side of the passage unit, the second bent portion extending throughout from the first end to the second end of the second main wall, 
 the passage units stacked such that the first contacting portions and the second contacting portions contact each other between the adjacent passage units, first fluid passages through which the first fluid flows are provided by the first outer spaces and the second outer spaces between the adjacent passage units, and core end walls are provided by at least one of the first side walls and the second side walls, 
 the fins disposed inside of the second fluid passages and held between the first and second bent portions; and 
   header tanks disposed at ends of the core, the header tanks providing tank inner spaces therein with the core end walls, the tank inner spaces being in communication with the first fluid passages.   
   
   
       2 . A heat exchanger according to  claim 1 , wherein
 the first main wall and the first side walls have substantially right-angled outer corners therebetween, and   the second main wall and the second side walls have substantially right-angled outer corners therebetween.   
   
   
       3 . A heat exchanger according to  claim 1 , wherein
 each of the second side walls includes a base portion connecting to the second main wall, a step portion and an opposed portion extending from the base portion through the step portion,   the opposed portion is located more to inside of the passage unit than the base portion with respect to a direction perpendicular to the unit stacking direction and is opposed to the first side wall such that an outer surface of the base portion is coplanar with an outer surface of the first side wall,   an end of the first side wall has an inclined surface that is inclined relative to the direction perpendicular to the unit stacking direction, and the inclined surface contacts an outer surface of the step portion.   
   
   
       4 . The heat exchanger according to  claim 1 , wherein
 the first side walls are overlapped with the second side walls such that inner surfaces of the first side walls contact outer surfaces of the second side walls and ends of the first side walls contact outer surfaces of the adjacent passage units,   the core end walls are provided by the outer surfaces of the first side walls, and   the end of each first side wall has an inclined surface that is inclined to separate from the outer surface of the second side wall as a function of distance from the first main wall in each first passage member.   
   
   
       5 . The heat exchanger according to  claim 1 , wherein
 each of the header tanks includes a body portion providing the tank inner space and tank engagement portions at opposite ends of the body portion with respect to the unit stacking direction,   the tank engagement portions are engaged with the core and hold the core with respect to the unit stacking direction.   
   
   
       6 . The heat exchanger according to  claim 5 , wherein
 each of the heater tanks includes a flange portion on a periphery of the body portion,   the flange portion contacts the core end wall,   the heat exchanger further comprising:   a duct member defining a duct passage through which the second fluid flows, the duct member connected to the core such that the duct passage is in communication with the second fluid passages provided inside of the passage units, wherein   the duct member has a duct engagement portion overlapped with the flange to hold the core in the direction perpendicular to the unit stacking direction.   
   
   
       7 . The heat exchanger according to  claim 5 , further comprising:
 a duct member having a duct main portion with a substantially tubular shape and a duct engagement portion extending from an end of the duct main portion, wherein   the duct engagement portion has a substantially tubular shape having a cross-section greater than a cross-section of the duct main portion, and   the duct member is connected to the core such that the duct main portion is in communication with the second fluid passages and the duct engagement portion surrounds an outer periphery of the core.   
   
   
       8 . The heat exchanger according to  claim 1 , further comprising:
 a duct member defining a duct passage through which the second fluid flows, the duct member connected to the core such that the duct passage is in communication with the second fluid passage provided inside of the passage units, wherein   the duct member has a duct engagement portion that is engaged with the core and hold the core with respect to a direction perpendicular to the unit stacking direction.   
   
   
       9 . The heat exchanger according to  claim 8 , wherein
 the passage units have openings in a second fluid flow direction that is perpendicular to the unit stacking direction and a flow direction of the first fluid in the first fluid passages, and   the duct member is connected to the core with respect to the second fluid flow direction.   
   
   
       10 . The heat exchanger according to  claim 1 , wherein
 the first bent portion has a first rib projecting outside of the passage unit,   the second bent portion has a second rib projecting outside of the passage unit, and   the first rib contacts the second rib of the adjacent passage unit.