Flush water tank device, and flush toilet apparatus including the same

Abstract

The present invention provides a flush water tank device, including a flush water tank main body including a first tank part and a second tank part for storing flush water, a rim spouting switch mechanism that switches discharge and stop of flush water in the first tank part, and a jet spouting discharge valve that switches discharge and stop of flush water in the second tank part, the first tank part and the second tank part are configured to have different cross-sectional areas depending on a height, and a ratio of the cross-sectional area of the first tank part to that of the second tank part at a first height is different from a ratio of the cross-sectional area at a second height that is lower than the first height.

1 . A flush water tank device that is attached to a flush toilet main body for use to supply flush water, comprising:
 a flush water tank main body including a first tank part and a second tank part that store flush water supplied to the flush toilet main body,   a rim spouting switch mechanism that switches discharge and stop of flush water in the first tank part so that the flush water in the first tank part is spouted from a rim spout port of the flush toilet main body, and   a jet spouting discharge valve that switches discharge and stop of flush water in the second tank part so that the flush water in the second tank part is spouted from a jet spout port of the flush toilet main body, wherein   the first tank part and the second tank part are configured to have different cross-sectional areas depending on a height, and a ratio of the cross-sectional area of the first tank part to the cross-sectional area of the second tank part at a first height is different from a ratio of the cross-sectional area at a second height that is lower than the first height.   
     
     
         2 . The flush water tank device according to  claim 1 , wherein the second tank part is configured to have a cross-sectional area that is equal to or more than the cross-sectional area of the first tank part at the first height. 
     
     
         3 . The flush water tank device according to  claim 2 , wherein the second tank part includes a stepped portion provided at a height between the first height and the second height, and the second tank part is configured to have a reduced cross-sectional area below the stepped portion, while the first tank part is configured to have an enlarged cross-sectional area below the stepped portion. 
     
     
         4 . The flush water tank device according to  claim 2 , wherein an inner tank is disposed in the flush water tank main body, the second tank part is formed inside the inner tank, and the first tank part is formed inside the flush water tank main body and outside the inner tank. 
     
     
         5 . The flush water tank device according to  claim 3 , wherein the jet spouting discharge valve is configured to discharge the flush water in the second tank part so that a water level in the second tank part lowers from a predetermined initial water level to a predetermined jet dead water level, and the stepped portion is provided at a position that is lower than the jet dead water level. 
     
     
         6 . The flush water tank device according to  claim 3 , wherein the rim spouting switch mechanism is configured to discharge the flush water in the first tank part so that the water level in the first tank part lowers from the predetermined initial water level to a predetermined rim dead water level, and the stepped portion is provided at a position that is higher than the rim dead water level. 
     
     
         7 . The flush water tank device according to  claim 1 , wherein the first tank part and the second tank part are configured so that the ratio of the cross-sectional area is reversed at the first height and the second height. 
     
     
         8 . A flush toilet apparatus that is flushed with flush water stored in a flush water tank, comprising:
 a flush toilet main body including a bowl, a rim spout port, and a jet spout port, and   the flush water tank device according to  claim 1 , which supplies flush water to the rim spout port and the jet spout port of the flush toilet main body.