Expansion tank

Abstract

An expansion tank includes a plurality of partition walls separating a storage chamber of the tank main body into a plurality of compartment chambers, each partition wall provided with a lower communicating portion and an upper communicating portion formed in a lower part and an upper part thereof, respectively, to communicate the adjoining compartment chambers to each other, wherein the compartment chambers include an inlet chamber having an inlet, an outlet chamber having an outlet, and intermediate chambers, and wherein one of the compartment chambers other than the outlet chamber is provided with a communication port, and a lower edge of the upper communicating portion of the partition wall defining the compartment chamber provided with the communication port is lower than a lower edge of the upper communicating portion of another one of the partition walls.

1 . An expansion tank, comprising:
 a tank main body defining a storage chamber for storing a coolant liquid therein; and   a plurality of partition walls separating the storage chamber into a plurality of compartment chambers;   wherein the partition walls include one provided with a lower communicating portion and an upper communicating portion formed in a lower part and an upper part thereof, respectively, to communicate the adjoining compartment chambers to each other;   wherein the compartment chambers include an inlet chamber having an inlet, an outlet chamber having an outlet, and at least one intermediate chamber; and   wherein one of the compartment chambers other than the outlet chamber is provided with a communication port, and a lower edge of the upper communicating portion of the partition wall defining the compartment chamber provided with the communication port is lower than a lower edge of the upper communicating portion of another one of the partition walls.   
     
     
         2 . The expansion tank according to  claim 1 , wherein the tank main body is box-shaped and has an open upper end which is closed by a top lid, and each upper communicating portion is defined between the corresponding partition wall and the top lid. 
     
     
         3 . The expansion tank according to  claim 1 , wherein at least one of the upper communicating portions consists of an opening having a lower edge defined by at least a part of an upper edge of the corresponding partition wall. 
     
     
         4 . The expansion tank according to  claim 2 , wherein the at least one intermediate chamber includes a first intermediate chamber and a second intermediate chamber, and the communication port is provided in the first intermediate chamber adjoining the inlet chamber, the first intermediate chamber and the inlet chamber adjoining the second intermediate chamber on a same side, and
 wherein a part of the partition walls defining the first intermediate chamber adjoining the partition wall defining the second intermediate chamber has an upper edge higher than an upper edge of a remaining part of the partition walls.   
     
     
         5 . The expansion tank according to  claim 4 , wherein the communication port communicates with the first intermediate chamber, and an upper edge of the partition wall separating the first intermediate chamber from the inlet chamber is higher than an upper edge of the partition wall separating the first intermediate chamber from one of the compartment chambers other than the inlet chamber. 
     
     
         6 . The expansion tank according to  claim 1 , wherein an opening area of the upper communicating portion of the partition wall defining the compartment chamber communicating with the communication port is greater than an opening area of the lower communicating portion of the partition wall defining the compartment chamber communicating with the communication port.