Oil cooler

Abstract

An oil cooler including a plurality of core plates stacked on each other, the plurality of core plates each including a base wall and a circumferential wall formed along an entire outer periphery of the base wall, and oil passages and cooling water passages alternately arranged in the direction of stacking the core plates. The core plates include at least a first core plate and a second core plate that is different from the first core plate in construction. The circumferential wall of the second core plate has a height being varied along a circumferential direction of the base wall. The circumferential wall of the second core plate is partially higher than the circumferential wall of the first core plate.

1 . An oil cooler comprising:
 a plurality of core plates stacked on each other, the plurality of core plates each comprising a base wall and a circumferential wall formed along an entire outer periphery of the base wall, the circumferential wall being inclined relative to the base wall so as to outwardly extend from the entire outer periphery of the base wall, the circumferential walls of the core plates which are disposed adjacent to each other in a direction of stacking the core plates being bonded to each other, and   oil passages and cooling water passages alternately arranged in the direction of stacking the core plates, the respective oil passages and the respective cooling water passages being formed in a clearance between the base walls adjacent to each other in the direction of stacking the core plates,   wherein the core plates comprise at least a first core plate and a second core plate that is different from the first core plate in construction, and the circumferential wall of the second core plate has a height being varied along a circumferential direction of the base wall, and the circumferential wall of the second core plate is partially higher than the circumferential wall of the first core plate.   
     
     
         2 . The oil cooler as claimed in  claim 1 , wherein the height of the circumferential wall of the second core plate is continuously varied along the entire outer periphery of the base wall, and the circumferential wall of the second core plate has an upper end located on a plane. 
     
     
         3 . The oil cooler as claimed in  claim 2 , wherein the plane is inclined relative to a plane parallel with the base wall of the second core plate. 
     
     
         4 . The oil cooler as claimed in  claim 3 , wherein the base wall of the second core plate has a disk shape. 
     
     
         5 . The oil cooler as claimed in  claim 1 , wherein the circumferential wall of the second core plate comprises a portion at which the height is continuously varied, and the portion has an upper end located on a plane. 
     
     
         6 . The oil cooler as claimed in  claim 5 , wherein the plane is inclined relative to a plane parallel with the base wall of the second core plate. 
     
     
         7 . The oil cooler as claimed in  claim 5 , wherein the portion of the circumferential wall of the second core plate is a half range of the entire circumferential wall along the circumferential direction of the base wall. 
     
     
         8 . The oil cooler as claimed in  claim 6 , wherein the base wall of the second core plate has a disk shape. 
     
     
         9 . The oil cooler as claimed in  claim 5 , wherein the circumferential wall of the second core plate comprises a portion at which the height is held constant, the portion having an upper end located on a plane that lies on a plane parallel with the base wall. 
     
     
         10 . The oil cooler as claimed in  claim 1 , wherein the base wall of the first core plate comprises a pair of oil communication holes through which the oil passages are communicated with each other in the direction of stacking the core plates, and a pair of cooling water communication holes through which the cooling water passages are communicated with each other in the direction of stacking the core plates, the pair of oil communication holes being symmetrically arranged with respect to a center of the base wall,
 the circumferential wall of the first core plate has a constant height over the entire outer periphery of the base wall of the first core plate, and   the base wall of the second core plate comprises one oil communication hole aligned with one of the pair of oil communication holes of the base wall of the first core plate, the base wall of the second core plate blocking a flow of oil passing through the other of the pair of oil communication holes of the base wall of the first core plate such that a direction of a flow of oil passing through the oil cooler is changed to a direction perpendicular to the direction of stacking the core plates.   
     
     
         11 . The oil cooler as claimed in  claim 1 , wherein the circumferential wall of the second core plate includes a portion at which the height is a minimum equal to a height of the circumferential wall of the first core plate.