Heat exchanger

Abstract

The present invention relates to a heat exchanger, and more particularly, to an integrated heat exchanger in which two or more coolants, which circulate through different cooling lines, are cooled by a single heat exchanger, and thermal stress, which occurs at a boundary portion between the two coolants because the two coolants have different temperature ranges, is dispersed or mitigated by designing and modifying structures of a header, a tank, a gasket, a support, and the like, thereby improving durability, sealability, robustness, and the like of the heat exchanger.

What is claimed is: 
     
         1 . A heat exchanger comprising:
 a core part comprising a first tube in which a first coolant flows, and a second tube in which a second coolant, which is different in temperature from the first coolant, flows;   a pair of header tanks having flow paths through which the first coolant and the second coolant flow independently of each other, the pair of header tanks being provided at two opposite ends of the core part based on a longitudinal direction of the core part; and   a gasket provided on a coupling portion between a header and the tank of each of the header tanks,   wherein the gasket comprises side gaskets configured to define an outer periphery and disposed outside the first tube and the second tube, and a center gasket provided inside the side gaskets and disposed between the first tube and the second tube,   wherein the header comprises side gasket seating portions on which the side gaskets are seated, and a center gasket seating portion on which the center gasket is seated,   wherein bottom surfaces of the side gasket seating portions and a bottom surface of the center gasket seating portion are formed on the same plane,   wherein a welding portion inner height of the first tube is equal to or smaller than a welding portion outer height of the first tube,   wherein a welding portion inner height of the second tube is equal to or smaller than a welding portion outer height of the second tube,   (wherein the welding portion inner height of the first tube corresponds to a distance to the plane from a lower end point of an end of a first welding portion where the first tube and the header are welded, the end of the first welding portion between adjacent to the center gasket seating portion,   wherein the welding portion outer height of the first tube corresponds to a distance to the plane from a lower end point of an end of the first welding portion adjacent to the side gasket seating portion,   wherein the welding portion inner height of the second tube corresponds to a distance to the plane from a lower end point of an end of a second welding portion where the second tube and the header are welded, the end of the second welding portion being adjacent to the center gasket seating portion, and   wherein the welding portion outer height of the second tube corresponds to a distance to the plane from a lower end point of an end of the second welding portion adjacent to the side gasket seating portion).   
     
     
         2 . The heat exchanger of  claim 1 , wherein the welding portion inner height of the first tube and the welding portion inner height of the second tube are each 2 mm or less. 
     
     
         3 . The heat exchanger of  claim 2 , wherein the welding portion inner height of the first tube and the welding portion outer height of the first tube are equal to each other, and the welding portion inner height of the second tube and the welding portion outer height of the second tube are equal to each other. 
     
     
         4 . The heat exchanger of  claim 1 , wherein a thickness of the center gasket is larger than a thickness of the side gasket. 
     
     
         5 . The heat exchanger of  claim 4 , wherein the center gasket comprises:
 a central portion having a thickness constant in an extension direction; and   tapered portions provided outside the central portion and each having a thickness that decreases in a direction away from the central portion.   
     
     
         6 . The heat exchanger of  claim 1 , wherein a width of the side gasket of the gasket is larger than a width of the center gasket. 
     
     
         7 . The heat exchanger of  claim 1 , wherein the gasket has a plurality of bridges spaced apart from one another and configured to connect the side gaskets to the center gasket in a perpendicular direction. 
     
     
         8 . The heat exchanger of  claim 7 , wherein the bridges are disposed to be symmetric with respect to the side gasket. 
     
     
         9 . The heat exchanger of  claim 1 , wherein the tank comprises a baffle configured to bisect an internal space of the header tank, and
 wherein protrusion portions are respectively formed on a lower end surface of the tank and a lower end surface of the baffle, and the protrusion portions sharply protrude downward and are elongated in an extension direction of the tank.   
     
     
         10 . The heat exchanger of  claim 1 , wherein the tank has a concave portion formed as one side of an upper surface of the tank is formed concavely toward an internal space of the header tank in an extension direction of the tank, and
 wherein a baffle, which bisects the internal space of the header tank, extends from the concave portion toward the header.   
     
     
         11 . The heat exchanger of  claim 10 , wherein a height of one side tank positioned at one side based on the concave portion of the tank is equal to a height of the other side tank positioned at the other side. 
     
     
         12 . The heat exchanger of  claim 10 , wherein a height of one side tank positioned at one side based on the concave portion of the tank is different from a height of the other side tank positioned at the other side. 
     
     
         13 . The heat exchanger of  claim 10 , wherein a length of the baffle is equal to or larger than half a maximum height of the tank. 
     
     
         14 . The heat exchanger of  claim 1 , further comprising:
 a support provided between the pair of header tanks and disposed outside the core part based on a width direction,   wherein a gap portion is formed in the support as partial regions of the support are spaced apart from each other at a predetermined interval.   
     
     
         15 . The heat exchanger of  claim 14 , wherein the gap portions are respectively formed at a point, which corresponds to a distance of 0.23 or more and 0.33 or less of an overall length of the support from one side of the support, and a point that corresponds to a distance of 0.23 or more and 0.33 or less of the overall length of the support from the other side of the support. 
     
     
         16 . The heat exchanger of  claim 14 , wherein a connection bridge is formed in the gap portion and connects one side support portion and the other side support portion that are spaced apart from each other based on the gap portion. 
     
     
         17 . The heat exchanger of  claim 16 , wherein the connection bridge of the gap portion is disposed between the first tube and the second tube.