System for controlling construction machinery and method for controlling construction machinery

Patent metadata

Field	Value
Publication number	US-2019218751-A1
Application number	US-201716332698-A
Country	US
Kind code	A1
Filing date	Sep 12, 2017
Priority date	Sep 12, 2016
Publication date	Jul 18, 2019
Grant date	—

Abstract

A control system for construction machinery, includes a hydraulic pump, first and second actuators connected to the hydraulic pump through first and second parallel lines respectively, first and second control valves installed in the first and second parallel lines respectively and configured to control operations of the first and second actuators, first and second spool displacement adjusting valves configured to control displacement amounts of the spools of the first and second control valves, and a control valve control portion configured to output the control signal, and configured to limit a maximum allowable value of the manipulation signal for the first actuator to a value selected by the operator and limit a spool displacement amount of the second control valve according to the limited manipulation signal for the first actuator when the manipulation signal for a multiple operation of the first and second actuators is received.

First claim

1 . A control system for construction machinery, comprising:
a first hydraulic pump; first and second actuators connected to the first hydraulic pump through first and second parallel lines respectively and operable by a working oil discharged from the first hydraulic pump; first and second control valves installed in the first and second parallel lines respectively and configured to control operations of the first and second actuators; first and second spool displacement adjusting valves configured to supply a pilot signal pressure to spools of the first and second control valves in proportion to an inputted control signal to control displacement amounts of the spools of the first and second control valves; and a control valve control portion configured to output the control signal to the first and second spool displacement adjusting valves corresponding to a manipulation signal of an operator, and configured to limit a maximum allowable value of the manipulation signal for the first actuator to a value selected by the operator and limit a spool displacement amount of the second control valve according to the limited manipulation signal for the first actuator when the manipulation signal for a multiple operation of the first and second actuators is received.

2 . The control system for construction machinery of claim 1 , wherein the control valve control portion converts a size of the manipulation signal for the first actuator at a ratio selected by the operator and outputs, to the second spool displacement adjusting valve, the control signal which is capable of decreasing a conversion ratio of a spool displacement of the second control valve to the manipulation signal for the second actuator in proportion to the size of the converted manipulation signal for the first actuator.

3 . The control system for construction machinery of claim 1 , wherein the first and second spool displacement adjusting valves include an electro proportional pressure reducing valve (EPPRV).

4 . The control system for construction machinery of claim 1 , wherein the control valve control portion comprises
a first joystick converter to convert an inputted first joystick displacement amount for the first actuator into a secondary first joystick displacement amount having a value reduced at the limiting ratio selected by the operator; a second joystick converter to convert an inputted second joystick displacement amount for the second actuator into a secondary second joystick displacement amount having a value that is reduced in proportion to the secondary first joystick displacement amount of the first actuator; and an output portion to output the control signal for controlling the pilot signal pressure in proportion to the secondary first joystick displacement amount and the secondary second joystick displacement amount.

5 . The control system for construction machinery of claim 1 , further comprising:
a secondary hydraulic pump driven by an engine which drives the first hydraulic pump and configured to supply a working oil to the second actuator; and a pump control portion configured to control discharge pressures of the first and second hydraulic pumps according to a horsepower distribution ratio.

6 . The control system for construction machinery of claim 5 , wherein the pump control portion controls a horsepower ratio of the first and second hydraulic pumps according to the horsepower distribution ratio selected by the operator.

7 . The control system for construction machinery of claim 5 , wherein a range of the limiting ratio of the manipulation signal selected by the operator is determined based on the horsepower distribution ratio.

8 . The control system for construction machinery of claim 1 , wherein the first actuator includes a swing motor and the second actuator includes a boom cylinder, and the first control valve includes a swing control valve and the second control valve includes a boom control valve.

9 . A control method for construction machinery, comprising:
providing a hydraulic system including first and second actuators connected to a first hydraulic pump through first and second parallel lines respectively and first and second control valves installed in the first and second parallel lines respectively and configured to control operations of the first and second actuators; receiving a manipulation signal of an operator for first and second actuators and a limiting ratio of the manipulation for the first actuator selected by an operator; limiting a maximum allowable value of the manipulation signal for the first actuator at the limiting ratio when the manipulation signal for a multiple operation of the first and second actuators is received; and limiting a spool displacement amount of the second control valve to the manipulation signal for the second actuator according to the limited manipulation signal for the first actuator.

10 . The control method for construction machinery of claim 9 , wherein limiting the maximum allowable value of the manipulation signal for the first actuator at the limiting ratio comprises converting a size of the manipulation signal for the first actuator at the limiting ratio selected by the operator, and
wherein limiting the spool displacement amount of the second control valve comprises decreasing a conversion ratio of the spool displacement of the second control valve to the manipulation signal for the second actuator in proportion to the size of the limited manipulation signal for the first actuator.

11 . The control method for construction machinery of claim 9 , wherein receiving the manipulation signal of the operator for first and second actuators comprises receiving joystick displacement amounts for the first and second actuators,
wherein limiting the maximum allowable value of the manipulation signal for the first actuator comprises converting the inputted first joystick displacement amount for the first actuator into a secondary first joystick displacement amount having a value reduced at the limiting ratio selected by the operator orifice, and wherein limiting the spool displacement amount of the second control valve comprises converting the inputted second joystick displacement amount for the second actuator into a secondary second joystick displacement amount having a value that is reduced in proportion to the secondary first joystick displacement amount of the first actuator.

12 . The control method for construction machinery of claim 11 , further comprising supplying a pilot signal pressure for controlling the spool displacements of the first and second control valves according to the secondary first joystick displacement amount and the secondary second joystick displacement amount, to spools of the first and second control valves.

13 . The control method for construction machinery of claim 12 , wherein the first and second spool displacement adjusting valves include an electro proportional pressure reducing valve (EPPRV).

14 . The control method for construction machinery of claim 9 , further comprising
providing a secondary hydraulic pump driven by an engine which drives the first hydraulic pump and configured to supply a working oil to the second actuator; and controlling discharge pressures of the first and second hydraulic pumps according to a horsepower distribution ratio.

15 . The control method for construction machinery of claim 11 , wherein controlling discharge pressures of the first and second hydraulic pumps comprises controlling a horsepower ratio of the first and second hydraulic pumps according to a horsepower distribution ratio selected b

Assignees

• Doosan Infracore Co Ltd

Inventors

• Kim Chang-Mook
• Jung Woo-Yong
• Ahn Hyeon-Sik
• Kim Ki-Yong

Classifications

• E02F9/2282

  Systems using center bypass type changeover valves · CPC title

• E02F9/2292

  Systems with two or more pumps · CPC title

• E02F9/2296

  Systems with a variable displacement pump · CPC title

• E02F9/2235

  including an electronic controller · CPC title

• F15B13/02

  Fluid distribution or supply devices characterised by their adaptation to the control of servomotors · CPC title