Working machine control system

Patent metadata

Field	Value
Publication number	US-10208457-B2
Application number	US-201515113071-A
Country	US
Kind code	B2
Filing date	Jan 27, 2015
Priority date	Jan 31, 2014
Publication date	Feb 19, 2019
Grant date	Feb 19, 2019

Abstract

A working machine control system includes: a split-flow fluid pressure pump configured to discharge a working fluid from a first discharge port and a second discharge port; a communication switching valve configured to allow, when one of a first operation valve and a second operation valve is switched, the first discharge port or the second discharge port for one of the first operation valve and the second operation valve that is not switched to communicate with a first neutral passage or a second neutral passage for the other of the first operation valve and the second operation valve that is switched; and a discharge flow rate adjusting device configured to adjust the fluid pressure pump so as to reduce a discharge flow rate of the fluid pressure pump in a case where a switch signal is inputted from any one of the first operation valve and the second operation valve.

First claim

The invention claimed is:

1. A working machine control system configured to control a working machine including a first actuator and a second actuator, the working machine control system comprising:
a split-flow 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 the working fluid discharged from the first discharge port is supplied, the first circuit system including a first operation valve and a first neutral passage, the first operation valve being configured to control the first actuator, the first neutral passage allowing the first discharge port to communicate with a tank in a state where the first operation valve is placed at a normal position;
a second circuit system to which the working fluid discharged from the second discharge port is supplied, the second circuit system including a second operation valve and a second neutral passage, the second operation valve being configured to control the second actuator, the second neutral passage allowing the second discharge port to communicate with the tank in a state where the second operation valve is placed at a normal position;
a communication switching valve configured to be switched between a first condition and a second condition,
in the first condition, the communication switching valve allowing the first discharge port to communicate with the second neutral passage,
in the second condition, the communication switching valve allowing the second discharge port to communicate with the first neutral passage; and

a discharge flow rate adjusting device configured to adjust the fluid pressure pump so as to reduce a discharge flow rate of the fluid pressure pump in a case where the switch signal is inputted from any one of the first operation valve and the second operation valve.

2. The working machine control system according to claim 1 , wherein the fluid pressure pump includes a swash plate whose inclination angle is adjusted by a single regulator to be controlled by a pilot pressure, and the inclination angle of the swash plate is adjusted in such a manner that the higher the pilot pressure acting on the regulator, the more the discharge flow rate increases.

3. The working machine control system according to claim 2 ,
wherein the communication switching valve is switched by a switch signal that is a pilot pressure for switching the first operation valve or the second operation valve,
wherein the discharge flow rate adjusting device includes:
a first high-pressure selection circuit configured to select the highest one of pilot pressures for switching the first operation valve to allow communication of the selected pilot pressure; and
a second high-pressure selection circuit configured to select the highest one of pilot pressures for switching the second operation valve to allow communication of the selected pilot pressure, and

wherein the communication switching valve includes:
a first communication switching valve so as to be switched, by the pilot pressure guided from the second high-pressure selection circuit, from a state where the second discharge port and the second neutral passage communicate with each other to a state where the second discharge port and the first neutral passage communicate with each other; and
a second communication switching valve so as to be switched, by the pilot pressure guided from the first high-pressure selection circuit, from a state where the first discharge port and the first neutral passage communicate with each other to a state where the first discharge port and the second neutral passage communicate with each other.

4. The working machine control system according to claim 3 ,
wherein the discharge flow rate adjusting device further includes:
a high-pressure selection valve configured to select higher one of the pilot pressures guided from the first high-pressure selection circuit and the second high-pressure selection circuit to cause the selected pilot pressure to act on the regulator; and
a differential pressure reduction valve configured to reduce the pilot pressure acting on the regulator as a pressure difference between the pilot pressures guided from the first high-pressure selection circuit and the second high-pressure selection circuit increases.

5. The working machine control system according to claim 4 ,
wherein the discharge flow rate adjusting device further includes a switching valve that is switched by the pilot pressure guided from the first high-pressure selection circuit and the pilot pressure guided from the second high-pressure selection circuit so that higher one of the pilot pressures guided from the first high-pressure selection circuit and the second high-pressure selection circuit is blocked and lower one of the pilot pressures is caused to act on the differential pressure reduction valve, and
wherein the differential pressure reduction valve reduces the pilot pressure acting on the regulator as a pressure difference between the pilot pressure acting on the regulator and the pilot pressure acting through the switching valve increases.

6. The working machine control system according to claim 2 ,
wherein the communication switching valve is switched by a switch signal that is an electric signal outputted via a switching operation for the first operation valve or the second operation valve,
wherein the discharge flow rate adjusting device includes:
a pilot pump configured to generate a pilot pressure;

a first pressure reduction valve configured to guide, when the electric signal is inputted only from the first operation valve, the pilot pressure from the pilot pump to the communication switching valve so as to allow the second discharge port and the first neutral passage to communicate with each other;
a second pressure reduction valve configured to guide, when the electric signal is inputted only from the second operation valve, the pilot pressure from the pilot pump to the communication switching valve so as to allow the first discharge port and the second neutral passage to communicate with each other; and
a third pressure reduction valve configured to reduce, when the electric signal is inputted from any one of the first operation valve and the second operation valve, the pilot pressure guided from the pilot pump to the regulator.

7. The working machine control system according to claim 1 , wherein
the first condition is a condition in which the communication switching valve is switched by a first switching signal for switching from the normal position of the first operation valve to a switched position, and
the second condition is a condition in which the communication switching valve is switched by a second switching signal for switching the normal position of the second operation valve to a switched position.

Assignees

• Kyb Corp

Inventors

• Yoshida Nobuyoshi
• Inagaki Ikuo

Classifications

• F15B2211/45

  Control of bleed-off flow, e.g. control of bypass flow to the return line · CPC title

• E02F9/2225 Primary

  using pressure-compensating valves · CPC title

• F15B2211/327

  electrically or electronically · CPC title

• E02F9/2267

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

• E02F9/2232

  using one or more variable displacement pumps · CPC title