Evaporator

Abstract

An evaporator includes a pair of header tanks spaced from each other in a vertical direction; a plurality of flat heat exchange tubes 45 which are disposed between the two header tanks such that their width direction coincides with a front-rear direction and they are spaced from one another in a left-right direction, opposite ends portions of the flat heat exchange tubes being connected to the corresponding header tanks; and corrugated fins 5 each disposed between adjacent heat exchange tubes 45 . Each of left and right portions of front and rear end walls 45 a of each heat exchange tube 45 has a straight slope portion 55 which inclines outward in the front-rear direction, toward a center portion of the heat exchange tube 45 with respect to the left-right direction. The angle formed between the slope portion 55 and the left edge or right edge of the corresponding corrugated fin 5 is set to 25 to 40 degrees.

1 . An evaporator comprising a pair of header tanks spaced from each other in a vertical direction; a plurality of flat heat exchange tubes which are disposed between the two header tanks such that their width direction coincides with a front-rear direction and they are spaced from one another in a left-right direction, opposite ends portions of the flat heat exchange tubes being connected to the corresponding header tanks; and corrugated fins each disposed between adjacent heat exchange tubes, wherein
 each of left and right portions of front and rear end walls of each heat exchange tube has a straight slope portion which inclines outward in the front-rear direction, toward a center portion of the heat exchange tube with respect to the left-right direction, and an angle formed between the slope portion and a left edge or right edge of the corresponding corrugated fin is 25 to 40 degrees.   
     
     
         2 . An evaporator according to  claim 1 , wherein left and right side surfaces of each heat exchange tube are in contact with the corresponding corrugated fins; and a ratio of a length W 2  (mm), as measured in the front-rear direction, of areas of contact between the left and right side surfaces of the heat exchange tube and the corresponding corrugated fins to a width W 1  (mm) of each heat exchange tube as measured in the front-rear direction is 80 to 95%. 
     
     
         3 . An evaporator according to  claim 1 , wherein each heat exchange tube has a width of 10 to 20 mm as measured in the front-rear direction. 
     
     
         4 . An evaporator according to  claim 1 , wherein each heat exchange tube has a thickness of 1 to 1.8 mm as measured in the left-right direction. 
     
     
         5 . An evaporator according to  claim 1  wherein a plurality of tube sets each composed of a plurality of flat heat exchange tubes spaced from one another in the front-rear direction are disposed between the upper and lower header tanks at predetermined intervals in the left-right direction; each of the fins is disposed between tube sets located adjacent to each other in the left-right direction; and, in each tube set composed of a plurality of the flat heat exchange tubes, a clearance is formed between the heat exchange tubes located adjacent to each other in the front-rear direction, the clearance having a width of 1.5 to 3.5 mm as measured in the front-rear direction. 
     
     
         6 . An evaporator according to  claim 1 , wherein each heat exchange tube is provided in a flat hollow body composed of two pressed rectangular metal plates laminated and joined together; the two metal plates which constitute the flat hollow body are bulged outward so as to form the heat exchange tube such that the heat exchange tube is open at upper and lower ends thereof; each of front and rear walls of an outward bulged portion of each metal plate which forms the heat exchange tube is straight and inclines outward in the front-rear direction, toward a thicknesswise center portion of the flat hollow body. 
     
     
         7 . An evaporator according to  claim 6 , wherein, at a front edge of each flat hollow body, one of the two metal plates has a protrusion formed over the entire length thereof such that a distal end portion of the protrusion projects beyond the other metal plate and toward the corrugated fin with which the other metal plate is in contact.