Liquid tank, breather device, and exhaust gas purification device for engine

Abstract

In a liquid tank provided with a pressure relief vent hole, a shielding member surrounding the vent hole is disposed. The shielding member forms an isolated chamber communicated with the vent hole. In a portion located to the side of the vent hole, the shielding member allows communication between the isolated chamber and an inner space in the liquid tank excluding the isolated chamber. On the other hand, in a portion located below the vent hole, the shielding member blocks movement of the liquid between the isolated chamber and the inner space.

1 . A liquid tank comprising:
 a tank main body configured to store a liquid therein, the tank main body including a vent hole enabling an interior of the tank main body to communicate with an exterior thereof; and   a shielding member attached to the tank main body so as to surround the vent hole within the tank main body, and to form an isolated chamber communicated with the vent hole, wherein   the shielding member includes a first portion located to the side of the vent hole in the horizontal direction and a second portion other than the first portion, the first portion forming an opening that communicates between the isolated chamber and an inner space of the tank main body excluding the isolated chamber, and in the second portion, the shielding member blocks movement of the liquid between the isolated chamber and the inner space.   
     
     
         2 . A liquid tank comprising:
 a tank main body configured to store a liquid therein, the tank main body including a vent hole enabling an interior of the tank main body to communicate with an exterior thereof; and   a shielding member attached to the tank main body so as to surround the vent hole within the tank main body, and form an isolated chamber communicated with the vent hole, wherein   the shielding member includes;   a first portion disposed at the side of the vent hole in the horizontal direction to enclose the vent hole, the first portion forming an opening that communicates between the isolated chamber and an inner space of the tank main body excluding the isolated chamber, and   a second portion located below the vent hole so as to block movement of the liquid between the isolated chamber and the inner space.   
     
     
         3 . The liquid tank according to  claim 1 , wherein the shielding member is constituted by a single member with a cross-section formed in a U-shape. 
     
     
         4 . The liquid tank according to  claim 1 , wherein the vent hole is provided in a lid part of the tank main body. 
     
     
         5 . The liquid tank according to  claim 1 , wherein
 the tank main body is of a rectangular in cross-section with the depth less than the width, and   the shielding member is longer in the width direction of the tank main body than in the depth direction thereof.   
     
     
         6 . The liquid tank according to  claim 5  provided for a vehicle, wherein
 the tank main body is fixed with respect to the vehicle, with the widthwise direction thereof aligned with the left to right direction of the vehicle.   
     
     
         7 . A liquid tank according to  claim 1  provided for a vehicle having an engine, further comprising a heat exchange pipe located inside the tank main body, and configured to circulate an coolant of the engine. 
     
     
         8 . The liquid tank according to  claim 7 , wherein the heat exchange pipe is located inside the tank main body, in contact with the shielding member. 
     
     
         9 . The liquid tank according to  claim 8 , wherein the heat exchange pipe is contacted with the shielding member via a heat transfer body. 
     
     
         10 . The liquid tank according to  claim 7  further comprising a pipe member forming a delivery passage for the liquid, and
 the heat exchange pipe is thermally contacted with the pipe member via the shielding member.   
     
     
         11 . The liquid tank according to  claim 10 , wherein
 the liquid is a urea aqueous solution, and   the pipe member is arranged to constitute a passage for delivering the urea aqueous solution stored in the tank main body, towards an exterior of the tank main body.   
     
     
         12 . The liquid tank according to  claim 1 , wherein the liquid is a urea aqueous solution. 
     
     
         13 . An exhaust gas purification device for an engine, comprising:
 the liquid tank according to  claim 1 , configured to be appropriate for storing a liquid reducing agent as the liquid;   a NOx reducing catalytic converter installed in an exhaust gas passage of the engine; and   a device configured to be capable of supplying the liquid reducing agent stored in the liquid tank, to exhaust gas on the upstream of the reducing catalytic converter.   
     
     
         14 . A breather device for relieving the pressure inside a liquid tank, comprising:
 a breather pipe forming a vent hole that enables an interior of the liquid tank to communicate with an exterior thereof; and   a shielding member configured to be disposed with respect to the breather pipe, within the liquid tank so as to surround the vent hole, and to form an isolated chamber communicated with the vent hole, wherein   the shielding member includes a first portion and a second portion, and wherein   the first portion locates to the side of the vent hole in the horizontal direction to enclose the vent hole, and forms an opening that communicates between the isolated chamber and an inner space within the liquid tank excluding the isolated chamber, and   the second portion locates below the vent hole so as to block movement of liquid between the isolated chamber and the inner space.