US 12,258,744 B2
Flush water tank device and flush toilet apparatus provided with the same
Yuta Kondo, Kitakyushu (JP); Koichiro Hiwa, Kitakyushu (JP); Yuki Shimokawa, Kitakyushu (JP); Kenji Hatama, Kitakyushu (JP); and Haruki Matsuda, Kitakyushu (JP)
Assigned to TOTO LTD., Kitakyushu (JP)
Filed by TOTO LTD., Kitakyushu (JP)
Filed on Mar. 15, 2023, as Appl. No. 18/121,770.
Claims priority of application No. 2022-059285 (JP), filed on Mar. 31, 2022.
Prior Publication US 2023/0313512 A1, Oct. 5, 2023
Int. Cl. E03D 1/14 (2006.01); E03D 1/34 (2006.01)
CPC E03D 1/142 (2013.01) [E03D 1/34 (2013.01); E03D 2201/40 (2013.01)] 7 Claims
OG exemplary drawing
 
1. A flush water tank device that stores flush water for flushing a flush toilet, the flush water tank device comprising:
a flush water tank main body that includes a discharge port and is configured to store the flush water;
a water supply valve that causes the flush water supplied from a water supply source to flow into the flush water tank main body; and
a discharge valve that is provided in the flush water tank main body and is configured to open and close the discharge port to switch between discharging and stopping of the flush water stored in the flush water tank main body to the flush toilet,
wherein during a flush of the flush toilet, the discharge valve is opened until a water level in the flush water tank main body is lowered from a predetermined full water level to a predetermined dead water level, a lowering speed of the water level in the flush water tank main body changes at a predetermined inflection water level between the full water level and the dead water level,
wherein the flush water tank main body is formed so that a horizontal cross-sectional area on a side upper than the inflection water level is larger than a horizontal cross-sectional area on a side lower than the inflection water level, thereby the lowering speed of the water level between the inflection water level and the dead water level is faster than the lowering speed of the water level between the full water level and the inflection water level, and
wherein the flush water tank main body is configured so that a volume on one side with respect to a centerline in the horizontal direction of the flush water tank main body is larger than a volume on the other side, and the discharge valve is placed on the side having a larger volume with respect to the centerline in the horizontal direction of the flush water tank main body.