Work machine and control method for work machine

Abstract

A work machine includes a traveling unit, a work implement mounted to the traveling unit, a parking brake, and a controller. The controller restricts operation of the work implement in a state in which the parking brake is released, when the controller detects a fault that allows the work machine to remain operable.

1 . A work machine comprising:
 a traveling unit;   a work implement mounted to the traveling unit;   a parking brake; and   a controller configured to restrict operation of the work implement in a state in which the parking brake is released, when the controller detects a fault that allows the work machine to remain operable.   
     
     
         2 . The work machine according to  claim 1 , wherein
 when the controller detects the fault, in a state in which the parking brake is applied, the controller allows a release of restriction on operation of the work implement.   
     
     
         3 . The work machine according to  claim 1 , further comprising:
 a restriction-operating section configured to be operated by an operator, the restriction-operating section being configured to output a signal in order to restrict or release restriction on operation of the work implement to the controller,   when the controller detects the fault, in the state in which the parking brake is released, the controller transitioning to a state to restrict the operation of the work implement upon receipt of a signal to restrict the operation of the work implement from the restriction-operating section.   
     
     
         4 . The work machine according to  claim 1 , further comprising:
 a restriction-operating section configured to be operated by an operator, the restriction-operating section being configured to output a signal in order to restrict or release restriction on operation of the work implement to the controller,   when the controller detects the fault, in the state in which the parking brake is released, the controller not releasing the restriction on the operation of the work implement even after receiving a signal to release the restriction on the operation of the work implement from the restriction-operating section.   
     
     
         5 . The work machine according to  claim 2 , further comprising:
 a restriction-operating section configured to be operated by an operator, the restriction-operating section being configured to output a signal in order to restrict or release the restriction on the operation of the work implement to the controller,   when the controller detects the fault, in a state in which the parking brake is applied and that allows the release of the restriction on the operation of the work implement, the controller releasing the restriction on the operation of the work implement, upon receipt of a signal to release the restriction on the operation of the work implement from the restriction-operating section.   
     
     
         6 . The work machine according to  claim 1 , further comprising:
 a hydraulic actuator configured to drive the work implement; and   a restricting valve configured to stop a supply of hydraulic oil to the hydraulic actuator,   when the controller detects the fault, in the state in which the parking brake is released, the controller controlling the restricting valve to stop the supply of hydraulic oil to the hydraulic actuator so as to restrict the operation of the work implement.   
     
     
         7 . The work machine according to  claim 2 , further comprising:
 a hydraulic actuator configured to drive the work implement;   a restricting valve configured to stop a supply of hydraulic oil to the hydraulic actuator; and   a restriction-operating section configured to be operated by an operator, the restriction-operating section being configured to restrict or release the restriction on the operation of the work implement,   when the controller detects the fault,
 in the state in which the parking brake is released, the controller controlling the restricting valve to stop the supply of hydraulic oil to the hydraulic actuator, so as to restrict the operation of the work implement, and 
 in the state in which the parking brake is applied, the controller releasing a stop on the supply of hydraulic oil to the hydraulic actuator by the restricting valve, upon receipt of a signal for releasing the restriction on the operation of the work implement from the restriction-operating section. 
   
     
     
         8 . The work machine according to  claim 6 , further comprising:
 a work-implement valve configured to adjust the supply of hydraulic oil to the hydraulic actuator based on a pilot hydraulic pressure; and   a pilot valve configured to adjust a supply of hydraulic oil for the pilot hydraulic pressure to the work-implement valve,   the restricting valve stopping the supply of hydraulic oil to the hydraulic actuator by stopping the supply of hydraulic oil for the pilot hydraulic pressure to the work-implement valve.   
     
     
         9 . A control method for a work machine including a traveling unit and a work implement mounted to the traveling unit, the control method comprising:
 detecting a fault that allows the work machine to remain operable; and   restricting operation of the work implement in a state where a parking brake is released, when the fault is detected.