The patent badge is an abbreviated version of the USPTO patent document. The patent badge does contain a link to the full patent document.
The patent badge is an abbreviated version of the USPTO patent document. The patent badge covers the following: Patent number, Date patent was issued, Date patent was filed, Title of the patent, Applicant, Inventor, Assignee, Attorney firm, Primary examiner, Assistant examiner, CPCs, and Abstract. The patent badge does contain a link to the full patent document (in Adobe Acrobat format, aka pdf). To download or print any patent click here.
Patent No.:
Date of Patent:
Nov. 11, 2025
Filed:
Oct. 12, 2021
Hitachi High-tech Corporation, Tokyo, JP;
Nobuhiro Tsukada, Tokyo, JP;
Daisuke Akieda, Tokyo, JP;
Sho Iwasa, Tokyo, JP;
Yusuke Yota, Tokyo, JP;
Yuichiro Hashimoto, Tokyo, JP;
Hitachi High-Tech Corporation, Tokyo, JP;
Abstract
Provided is a technology for reducing the capacity of a liquid feeding pump and enabling liquid feeding with little pulsation. A liquid feeding pump according to the present disclosure is provided with: a first plunger pump having a first plunger; a second plunger pump having a second plunger and connected in series with the first plunger pump; a pressure sensor disposed downstream of the second plunger pump; and a control unit that accepts the input of a liquid discharge pressure measured by the pressure sensor and that controls the driving of the first plunger and the driving of the second plunger. The control unit calculates the rate of change in the pressure of the liquid on the basis of the past compression distances of the plunger for when the liquid was compressed by the first plunger pump and the pressure at the completion of compression, predicts the compression distance of the first plunger on the basis of the rate of change in pressure and the present discharge pressure, and determines the timing at which the compression performed by the first plunger will be completed on the basis of the predicted compression distance.