Fluid state detection sensor

Patent metadata

Field	Value
Publication number	US-2024167972-A1
Application number	US-202218283142-A
Country	US
Kind code	A1
Filing date	Mar 11, 2022
Priority date	Mar 30, 2021
Publication date	May 23, 2024
Grant date	—

Abstract

A fluid state detection sensor accurately detects a fluid state by suppressing the deterioration of a conductivity measurement accuracy due to its characteristics. The sensor includes an electrode section configured by a pair of electrodes arranged opposite each other, a conductivity acquisition unit detecting a resistance value from an inter-electrode voltage value acquired through the electrode section and acquiring a fluid conductivity, a controller executing entire sensor's processing according to a control program stored in ROM etc., a memory storing correction values for fluid whose conductivity is greater than a predetermined value calculated by a conductivity calculator, which calculates the fluid conductivity from the inter-electrode voltage value, a corrector correcting the conductivity calculator calculated conductivity using the correction value stored in the memory when the fluid whose conductivity calculator calculated conductivity is greater than the predetermined value, and an output section outputting corrected conductivity.

First claim

1 . A fluid state detection sensor comprising:
an electrode section placed in a fluid and configured by a pair of electrodes arranged opposite to each other; a conductivity acquisition unit comprising a voltage acquisitor configured to acquire an inter-electrode voltage value via the electrode section, and a conductivity calculator configured to detect a resistance value from the inter-electrode voltage value acquired at the voltage acquisitor and calculate a conductivity of the fluid; a memory configured to respectively store a base oil type, a conductivity of the base oil, and a correction value of the conductivity of the base oil whose conductivity is greater than a predetermined value; and a corrector configured to correct the conductivity calculated by the conductivity calculator using the correction value stored in the memory.

2 . The fluid state detection sensor according to claim 1 further comprising a relative permittivity acquisition unit and a correction value estimator,
wherein the fluid is a hydraulic oil,
wherein the relative permittivity acquisition unit comprises a relative permittivity calculator configured to detect a capacitance value from the inter-electrode voltage value acquired in the voltage acquisitor and calculate a relative permittivity of the hydraulic oil,
wherein the memory stores a database of a plurality of hydraulic oil information items that is linked with information including a base oil type of the hydraulic oil, the conductivity, and the relative permittivity, and
wherein the correction value estimator is configured to estimate the correction value of a hydraulic oil to be used using the hydraulic oil information of the hydraulic oil that approximates the hydraulic oil information among the plurality of hydraulic oil information items stored in the database, and to store the estimated correction value in the memory.

Assignees

• Kyb Corp

Inventors

• Yoshida Takahiro
• Kameda Yukinori
• Nagai Yuki
• Nakamura Ryohei

Classifications

• G01N27/028 Primary

  Circuits therefor (measuring impedance per se G01R27/02) · CPC title

• G01N27/06

  of a liquid (involving electrolysis G01N27/26) · CPC title

• G01N27/228

  Circuits therefor (measuring capacitance per se G01R27/26) · CPC title

• G01N33/28

  Oils {, i.e. hydrocarbon liquids} (edible oils or edible fats G01N33/03) · CPC title

• G01N27/08 Primary

  which is flowing continuously · CPC title