ACTUATOR CONTROL DEVICE

• US 20100126339A1
• Filed: 04/09/2008
• Published: 05/27/2010
• Est. Priority Date: 04/18/2007
• Status: Abandoned Application

• Current Assignee: Kayaba Industry Company Limited
• Original Assignee: Kayaba Industry Company Limited
• Inventors: Kobata, Hiroshi
• Application Number:
  US12/450,553
• Publication Number:
  US 20100126339A1
• Time in Patent Office: Days
• US Class Current: 91/444
• CPC Class Codes: E02F 9/2203 Arrangements for controlling the attitude of actuators, e.g. speed, floating function
• CPC Class Codes: F15B 11/006 Hydraulic "Wheatstone bridge" circuits, i.e. with four nodes, P-A-T-B, and on-off or proportional valves in each link
• CPC Class Codes: F15B 11/028 for controlling the actuating force F15B11/024 takes precedence
• CPC Class Codes: F15B 2211/20538 constant capacity
• CPC Class Codes: F15B 2211/30575 in a Wheatstone Bridge arrangement (also half bridges)
• CPC Class Codes: F15B 2211/3111 the pump port being closed in the centre position, e.g. so-called closed centre
• CPC Class Codes: F15B 2211/3144 the positions being continuously variable, e.g. as realised by proportional valves
• CPC Class Codes: F15B 2211/31576 having a single pressure source and a single output member
• CPC Class Codes: F15B 2211/327 electrically or electronically
• CPC Class Codes: F15B 2211/351 Flow control by regulating means in feed line, i.e. meter-in control
• CPC Class Codes: F15B 2211/353 Flow control by regulating means in return line, i.e. meter-out control
• CPC Class Codes: F15B 2211/6313 the pressure being a load pressure
• CPC Class Codes: F15B 2211/6346 representing a state of input means, e.g. joystick position
• CPC Class Codes: F15B 2211/6654 Flow rate control

Abstract

An actuator control device includes a meter-in solenoid valve (V1) and a meter-out solenoid valve (V2) that control the supply and discharge of a working fluid relative to an anti rod-side oil chamber (4a), a meter-in solenoid valve (V3) and a meter-out solenoid valve (V4) that control the supply and discharge of the working fluid relative to a rod-side oil chamber (4b), a plurality of maps defining characteristics of opening areas of the meter-in solenoid valves (V1, V3) and the meter-out solenoid valves (V2, V4) relative to an actuator speed command, and a controller programmed to determine an operating condition of the actuator on the basis of a detection result from a detector that detects operation information relating to the actuator, and select a map to be used in control from the plurality of maps in accordance with the operating condition of the actuator.

Claims

1. An actuator control device for controlling an actuator that drives a movable member of a construction machine, comprising:

the actuator, which is driven by a working fluid supplied from a pump;

a first meter-in solenoid valve and a first meter-out solenoid valve which respectively control the working fluid supplied to the actuator and the working fluid discharged from the actuator to drive the actuator in one direction;

a second meter-in solenoid valve and a second meter-out solenoid valve which respectively control the working fluid supplied to the actuator and the working fluid discharged from the actuator to drive the actuator in the other direction;

a plurality of maps defining characteristics of opening areas of the meter-in solenoid valves and the meter-out solenoid valves relative to a speed command relating to the actuator; and

a controller programmed to;

determine an operating condition of the actuator on the basis of a detection result from a detector that detects operation information relating to the actuator; and

select a map to be used in control from the plurality of maps in accordance with the operating condition of the actuator determined.

2. The actuator control device as defined in claim 1, wherein the actuator is a hydraulic cylinder comprising an anti rod-side oil chamber and a rod-side oil chamber in which the working fluid is sealed,

the first meter-in solenoid valve and the first meter-out solenoid valve control an expansion operation of the actuator,

the second meter-in solenoid valve and the second meter-out solenoid valve control a contraction operation of the actuator,

a pressure detector that detects a pressure of the rod-side oil chamber is provided,

the controller is programmed to:

determine that a load of the rod-side oil chamber is large when the pressure of the rod-side oil chamber is greater than a preset reference value, and

select a map on which an opening area of the first meter-out solenoid valve relative to the speed command relating to the actuator increases beyond a current opening area when the load of the rod-side oil chamber is determined to be large.

3. The actuator control device as defined in claim 1, wherein, during activation of the actuator, the meter-out solenoid valves are opened first, whereupon the meter-in solenoid valves are opened.

4. The actuator control device as defined in claim 1, wherein, during stoppage of the actuator, the meter-in solenoid valves are closed first, whereupon the meter-out solenoid valves are closed.