A slewing assist system for a machine having an upper body structure supported on an undercarriage structure includes a central rotation member. The central rotation member is rotatably coupled to undercarriage structure. A slip member is concentrically coupled to central rotation member and allows a relative rotational motion. At least one pin is coupled to slip member and engages slip member in expanded position such that central rotation member and slip member rotate together. A lever arm is fixedly coupled to slip member. A first end and a second end of an actuating element are coupled to lever arm and upper structure, respectively. The slewing assist system provides additional slewing assist to upper body structure by engaging slip member and central rotation member through pin. The slewing assist system assists in a first and a second rotational direction by extending and retracting second end of actuating element, respectively.

A working machine includes a lower body, a turning body, a turning manipulating member which turns the turning body, a hydraulic motor which rotationally drives the turning body, a brake device which brakes the hydraulic motor, amain hydraulic source which supplies hydraulic oil to the hydraulic motor, and a direction control valve which controls a flow direction of the hydraulic oil according to the manipulated variable of the turning manipulating member, in which in a state where the hydraulic motor is braked by the brake device based on a manipulation of a brake manipulating member, when the turning manipulation is performed by the turning manipulating member, a brake applied to the hydraulic motor by the brake device is released with respect to turning in an indication direction indicated by the turning manipulation such that the turning body turns in the indication direction.

A working machine includes a lower body, a turning body, a turning manipulating member which turns the turning body, a hydraulic motor which rotationally drives the turning body, a brake device which brakes the hydraulic motor, amain hydraulic source which supplies hydraulic oil to the hydraulic motor, and a direction control valve which controls a flow direction of the hydraulic oil according to the manipulated variable of the turning manipulating member, in which in a state where the hydraulic motor is braked by the brake device based on a manipulation of a brake manipulating member, when the turning manipulation is performed by the turning manipulating member, a brake applied to the hydraulic motor by the brake device is released with respect to turning in an indication direction indicated by the turning manipulation such that the turning body turns in the indication direction.

The present invention is configured so that it is possible to select any one of a first mode in which a first adjustment valve 13 and a second adjustment valve 20 operate solely on the basis of manipulation of a main manipulation tool (turning lever 8i), a second mode in which the first adjustment valve 13 operates solely on the basis of manipulation of the main manipulation tool (8i) and the second adjustment valve 20 operates solely on the basis of manipulation of a secondary manipulation tool (brake pedal 8j), and a third mode in which the first adjustment valve 13 operates solely on the basis of manipulation of the main manipulation tool (8i) and the second adjustment valve 20 operates on the basis of manipulation of the secondary manipulation tool (8j) while operating on the basis of manipulation of the main manipulation tool (8i).

The present invention is configured so that it is possible to select any one of a first mode in which a first adjustment valve 13 and a second adjustment valve 20 operate solely on the basis of manipulation of a main manipulation tool (turning lever 8i), a second mode in which the first adjustment valve 13 operates solely on the basis of manipulation of the main manipulation tool (8i) and the second adjustment valve 20 operates solely on the basis of manipulation of a secondary manipulation tool (brake pedal 8j), and a third mode in which the first adjustment valve 13 operates solely on the basis of manipulation of the main manipulation tool (8i) and the second adjustment valve 20 operates on the basis of manipulation of the secondary manipulation tool (8j) while operating on the basis of manipulation of the main manipulation tool (8i).

An obstacle detection device detects an obstacle existing in one or more monitoring areas that are set to correspond to a movable part. A state determination unit determines whether a state of the actuator is a standby state or a suspended state under circumstances where the actuator is at a stop. On determination that the state of the actuator is the standby state, a display control unit executes automatic image output that is processing for causing a display device to display a monitoring image corresponding to a monitoring area in which the obstacle is detected out of the one or more monitoring areas. On determination that the state of the actuator is the suspended state, the display control unit stops the execution of the automatic image output.

An obstacle detection device detects an obstacle existing in one or more monitoring areas that are set to correspond to a movable part. A state determination unit determines whether a state of the actuator is a standby state or a suspended state under circumstances where the actuator is at a stop. On determination that the state of the actuator is the standby state, a display control unit executes automatic image output that is processing for causing a display device to display a monitoring image corresponding to a monitoring area in which the obstacle is detected out of the one or more monitoring areas. On determination that the state of the actuator is the suspended state, the display control unit stops the execution of the automatic image output.

An informing device is an informing device mounted on a work vehicle that includes a lower base body, and a swivel body swivelably provided at the lower base body. The informing device includes a first detection unit that detects the actual amount of rotation of a drive device which swivels the swivel body or a driven part driven by the drive device, and a notification unit that issues a notification regarding information corresponding to the amount of rotation detected by the first detection unit.

The present disclosure relates to a hydraulic control circuit for crane slewing gear having directional valves arranged in work lines and controllable separately for the inflow and outflow to the hydraulic motor for the carrying out of a rotational movement of the slewing gear, wherein an inflow valve serves the control of the oil inflow from a hydraulic pump via the work line to the hydraulic motor and an outflow valve is provided via which the hydraulic motor can be relieved to the tank, wherein the work lines are each connected via at least one check valve to a common inlet of the outflow valve to relieve the hydraulic motor independently of the direction of rotation of the slewing gear via an outflow valve into the tank.

The present disclosure relates to a hydraulic control circuit for crane slewing gear having directional valves arranged in work lines and controllable separately for the inflow and outflow to the hydraulic motor for the carrying out of a rotational movement of the slewing gear, wherein an inflow valve serves the control of the oil inflow from a hydraulic pump via the work line to the hydraulic motor and an outflow valve is provided via which the hydraulic motor can be relieved to the tank, wherein the work lines are each connected via at least one check valve to a common inlet of the outflow valve to relieve the hydraulic motor independently of the direction of rotation of the slewing gear via an outflow valve into the tank.