Working machine control system and lower pressure selection circuit

Patent metadata

Field	Value
Publication number	US-2016265560-A1
Application number	US-201515032908-A
Country	US
Kind code	A1
Filing date	Jan 27, 2015
Priority date	Jan 31, 2014
Publication date	Sep 15, 2016
Grant date	—

Abstract

A working machine control system includes a split flow type fluid pressure pump configured to discharge a working fluid from a first discharge port and a second discharge port, and a lower pressure selection circuit configured to select and communicate with a working fluid of lower pressure among a working fluid on the downstream of a first operation valve of a first neutral passage in a first circuit system to which a working fluid discharged from the first discharge port is supplied, and a working fluid on the downstream of a second operation valve of a second neutral passage in a second circuit system to which a working fluid discharged from the second discharge port is supplied. The fluid pressure pump is adjusted in such a manner that the lower the pressure of the working fluid selected by the lower pressure selection circuit is, the more a discharge flow rate is increased.

First claim

1 . A working machine control system configured to control a working machine having a first actuator and a second actuator, comprising:
a split flow type fluid pressure pump configured to discharge a working fluid from a first discharge port and a second discharge port; a first circuit system to which a working fluid discharged from the first discharge port is supplied, the first circuit system having a first operation valve configured to control the first actuator, and a first neutral passage providing communication between the first discharge port and a tank in a state where the first operation valve is placed at a normal position; a second circuit system to which a working fluid discharged from the second discharge port is supplied, the second circuit system having a second operation valve configured to control the second actuator, and a second neutral passage providing communication between the second discharge port and the tank in a state where the second operation valve is placed at a normal position; and a lower pressure selection circuit configured to select and communicate with a working fluid of lower pressure among a working fluid on the downstream of the first operation valve of the first neutral passage, and a working fluid on the downstream of the second operation valve of the second neutral passage, wherein the fluid pressure pump includes a swash plate whose inclination angle is adjusted by a single regulator to be controlled with the pressure of the working fluid selected by the lower pressure selection circuit as pilot pressure, and the discharge flow rate is adjusted by the regulator, the fluid pressure pump being adjusted in such a manner that the lower the pressure of the working fluid selected by the lower pressure selection circuit is, the more a discharge flow rate is increased, and the lower pressure selection circuit includes: a higher pressure selection valve configured to select a working fluid on the high pressure side among the first neutral passage and the second neutral passage, and a switching valve to be switched by pressure of the working fluid selected by the higher pressure selection valve, the switching valve being configured to block the working fluid ont the high pressure side among the first neutral passage and the second neutral passage, and guide a working fluid on the low pressure side to the regulator as the pilot pressure,

2 . (canceled)

3 . (canceled)

4 . The working machine control system according to claim 1 , wherein
the switching valve includes: a first switching valve configured to block the working fluid from the first neutral passage; and a second switching valve configured to block the working fluid from the second neutral passage, wherein one of the first switching valve and the second switching valve is switched into a communication state by the pressure of the working fluid selected by the higher pressure selection valve, and the passing working fluid is guided to the regulator as the pilot pressure.

5 . A lower pressure selection circuit, comprising:
a higher pressure selection valve configured to select a working fluid on the high pressure side among a first fluid passage and a second fluid passage; and a switching valve to be switched by pressure of the working fluid selected by the higher pressure selection valve, the switching valve being configured to block the working fluid on the high pressure side among the first fluid passage and the second fluid passage, and communicate with a working fluid on the low pressure side.

Assignees

• Kyb Corp

Inventors

• Yoshida Nobuyoshi
• Inagaki Ikuo

Classifications

• E02F9/2267

  Valves or distributors (position of valves arrangements on upper-structures E02F9/0875) · CPC title

• F15B2211/20546

  variable capacity · CPC title

• E02F3/32

  working downwardly and towards the machine, e.g. with backhoes · CPC title

• E02F9/2235

  including an electronic controller · CPC title

• F15B11/10 Primary

  in which the servomotor position is a function of the pressure {also pressure regulators as operating means for such systems, the device itself may be a position indicating system} · CPC title