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:
Apr. 24, 2018

Filed:

Oct. 17, 2013
Applicants:

Hitachi Construction Machinery Co., Ltd., Bunkyo-ku, Tokyo, JP;

Takako Satake, Tsuchiura, JP;

Inventors:

Shinya Imura, Tokyo, JP;

Kouji Ishikawa, Tsuchiura, JP;

Hidetoshi Satake, Ishioka, JP;

Tomoaki Kaneta, Tsuchiura-shi, Ibaraki, JP;

Attorney:
Primary Examiner:
Assistant Examiner:
Int. Cl.
CPC ...
F15B 11/042 (2006.01); E02F 9/22 (2006.01); E02F 9/24 (2006.01); F04B 49/22 (2006.01); E02F 9/26 (2006.01); F15B 11/08 (2006.01); F15B 13/02 (2006.01);
U.S. Cl.
CPC ...
F15B 11/0423 (2013.01); E02F 9/2225 (2013.01); E02F 9/2235 (2013.01); E02F 9/2285 (2013.01); E02F 9/2292 (2013.01); E02F 9/2296 (2013.01); E02F 9/24 (2013.01); E02F 9/268 (2013.01); F04B 49/22 (2013.01); F15B 11/08 (2013.01); F15B 13/02 (2013.01); F15B 2211/20546 (2013.01); F15B 2211/3116 (2013.01); F15B 2211/40515 (2013.01); F15B 2211/41581 (2013.01); F15B 2211/45 (2013.01); F15B 2211/6346 (2013.01); F15B 2211/665 (2013.01); F15B 2211/6652 (2013.01); F15B 2211/6658 (2013.01);
Abstract

Provided is a work machine including: a variable-displacement pump; an actuatordriven by a hydraulic fluid delivered from the pump; a flow control valveof an open-center type that controls a flow rate of the hydraulic fluid supplied to the actuator; a bleed-off lineconnecting the actuator flow control valveto a tank; a bleed-off flow control valvedisposed in the bleed-off line; an operating devicethat specifies operation of the actuator; a bleed-off control devicethat controls a degree of opening of the bleed-off flow control valvein accordance with an amount of manipulation of the operating device; and a pump control devicethat controls, in accordance with the degree of opening of the bleed-off flow control valve, a pump flow rate by correcting a reference pump flow rate that is based on the amount of manipulation of the operating device. The work machine with this configuration can save energy while at the same time inhibiting an occurrence of a sense of strangeness or discomfort in particular operation.


Find Patent Forward Citations

Loading…