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.

Date of Patent:
Jun. 04, 2024

Filed:

Mar. 12, 2021
Applicant:

Hitachi Construction Machinery Co., Ltd., Tokyo, JP;

Inventors:

Kento Kumagai, Ami-machi, JP;

Shinya Imura, Toride, JP;

Yasutaka Tsuruga, Ryugasaki, JP;

Takaaki Chiba, Kasumigaura, JP;

Hiroaki Amano, Tsukuba, JP;

Shinji Nishikawa, Kasumigaura, JP;

Akihiro Narazaki, Tsukuba, JP;

Attorney:
Primary Examiner:
Assistant Examiner:
Int. Cl.
CPC ...
F15B 21/045 (2019.01); E02F 9/20 (2006.01); E02F 9/22 (2006.01); E02F 9/26 (2006.01); F15B 13/02 (2006.01); F15B 13/044 (2006.01); E02F 3/32 (2006.01); E02F 3/42 (2006.01); E02F 3/43 (2006.01);
U.S. Cl.
CPC ...
F15B 21/045 (2013.01); E02F 9/2004 (2013.01); E02F 9/2203 (2013.01); E02F 9/2228 (2013.01); E02F 9/2267 (2013.01); E02F 9/2271 (2013.01); E02F 9/2285 (2013.01); E02F 9/2292 (2013.01); E02F 9/26 (2013.01); F15B 13/025 (2013.01); F15B 13/044 (2013.01); E02F 3/32 (2013.01); E02F 3/425 (2013.01); E02F 3/435 (2013.01); E02F 9/2296 (2013.01); F15B 2211/30535 (2013.01); F15B 2211/6343 (2013.01); F15B 2211/6654 (2013.01);
Abstract

A work machine that can keep the control accuracy of actuators irrespective of temperature variation of a hydraulic operating fluid that passes through flow rate controllers that control the flow rates of supply to the actuators is provided. For this purpose, the flow rate controllers each have a valve body that is disposed on a main hydraulic line connecting a delivery line of a hydraulic pump and the actuator and that moves according to an operation pressure from a solenoid proportional pressure reducing valve, a sampling hydraulic line that branches from the main hydraulic line, and a temperature sensor set on the sampling hydraulic line. The controller is configured to correct a command electrical signal to the solenoid proportional pressure reducing valve according to a signal from the temperature sensor.


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