US 12,467,908 B2
Liquid feeding pump and liquid feeding method
Nobuhiro Tsukada, Tokyo (JP); Daisuke Akieda, Tokyo (JP); Sho Iwasa, Tokyo (JP); Yusuke Yota, Tokyo (JP); and Yuichiro Hashimoto, Tokyo (JP)
Assigned to Hitachi High-Tech Corporation, Tokyo (JP)
Appl. No. 18/032,717
Filed by Hitachi High-Tech Corporation, Tokyo (JP)
PCT Filed Oct. 12, 2021, PCT No. PCT/JP2021/037736
§ 371(c)(1), (2) Date Apr. 19, 2023,
PCT Pub. No. WO2022/107500, PCT Pub. Date May 27, 2022.
Claims priority of application No. 2020-192248 (JP), filed on Nov. 19, 2020.
Prior Publication US 2023/0384271 A1, Nov. 30, 2023
Int. Cl. F04B 23/06 (2006.01); F04B 49/06 (2006.01); F04B 51/00 (2006.01); G01N 30/32 (2006.01)
CPC G01N 30/32 (2013.01) [F04B 23/06 (2013.01); F04B 49/06 (2013.01); F04B 51/00 (2013.01); G01N 2030/326 (2013.01)] 13 Claims
OG exemplary drawing
 
1. A liquid feeding pump comprising:
a first plunger pump including a first plunger;
a second plunger pump including a second plunger and connected to the first plunger pump in series;
a single pressure sensor disposed downstream from the second plunger pump; and
a control unit configured to receive an input of a discharge pressure of a liquid measured by the single pressure sensor and control driving of the first plunger and driving of the second plunger based on the input from only the single pressure sensor, wherein
the control unit calculates a pressure change rate of the liquid based on a past compression distance of the first plunger while the liquid is compressed by the first plunger pump and a pressure while the compression is completed, predicts a compression distance of the first plunger based on the pressure change rate and a current discharge pressure, and determines when the compression by the first plunger is completed based on the predicted compression distance.