Abstract: A control method controls a movable member of an excavator including a movable member holding a load, an actuator with electric motor and static brake, a control unit and a motion sensor unit. Static brake and electric motor generate respectively an upper threshold brake force and an upper threshold motor force. The control method includes: an immobilization step: static brake generates the upper threshold brake force and the electric motor is stopped; a slippage detection step: the control unit detects whether electric actuator is moving despite the static brake, in case the electric actuator is moving, a motor energizing step: electric motor generates a motor force equal or superior to upper threshold brake force in a direction opposite to the slippage direction, and after the motor energizing step, a brake release step: the control unit releases the static brake.
Type:
Application
Filed:
April 3, 2015
Publication date:
March 15, 2018
Applicant:
VOLVO CONSTRUCTION EQUIMENT AB
Inventors:
Lilian BRUYERE, Ahcène NEDJIMI, François SAVOYE, Roger CAILLIERET
Abstract: A flow rate control apparatus for construction equipment includes: a boom cylinder driven by hydraulic fluid; a first control valve for controlling a hydraulic fluid flow supplied to the boom cylinder; an option actuator driven by hydraulic fluid; a second control valve for controlling a hydraulic fluid flow supplied to the option actuator; a boom cylinder manipulation lever and an option actuator manipulation lever; a confluence line selectively confluence the hydraulic fluid supplied to the boom cylinder with the hydraulic fluid of the option actuator; a center bypass switching valve provided at the furthest downstream side of a fluid supply path of the first hydraulic pump; a confluence switching valve selectively opening and closing the confluence line; a confluence selection valve applying a pilot pressure to the confluence switching valve; and a controller for controlling the confluence selection valve.