Brake device for braking a hydraulic motor of a turning body in a working machine

A working machine comprising:

• a lower body;
• a turning body which is turnably provided on the lower body;
• a turning manipulating member configured to turn the turning body;
• a hydraulic motor configured to rotationally drive the turning body according to a manipulated variable of the turning manipulating member;
• a brake device configured to brake the hydraulic motor;
• a main hydraulic source configured to supply hydraulic oil to the hydraulic motor;
• a direction control valve which is provided between the main hydraulic source and the hydraulic motor and is configured to control a flow direction of the hydraulic oil according to the manipulated variable of the turning manipulating member;
• and
• a pilot hydraulic source for generating a pilot pressure,
• wherein in a state where the hydraulic motor is braked by the brake device based on a manipulation of a brake manipulating member, in a case where 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,
• wherein the direction control valve is operated by the pilot pressure generated according to the manipulated variable of the turning manipulating member so as to control the flow direction of the hydraulic oil,
• wherein the brake device includes
• a pair of brake control valves which is provided in front of and behind the hydraulic motor between the hydraulic motor and the direction control valve and is configured to operate between a closed position at which the flow of the hydraulic oil is blocked to brake the hydraulic motor and an open position at which the flow of the hydraulic oil is allowed, and
• the brake manipulating member configured to output a brake command of the hydraulic motor,
• wherein when the brake command is output from the brake manipulating member, each of the pair of brake control valves is in a brake state at which the brake control valve is held at the closed position,
• wherein in the brake state, when an operator manipulates the turning manipulating member, the pilot pressure is applied to a first brake control valve which is one of the pair of brake control valves, and the first brake control valve is switched to the open position, and
• wherein when the hydraulic oil discharged from the main hydraulic source bypasses a second brake control valve which is the other of the pair of brake control valves and is supplied to the hydraulic motor, the hydraulic motor is driven in the indication direction in the brake state.

A working machine comprising:

• a hydraulic motor configured to apply, to a turning body when a flow of hydraulic oil is applied to the hydraulic motor via a pipeline, a rotating force that rotates the turning body in a forward direction;
• and
• a brake device configured to apply, along a pathway other than the pipeline, a braking force that prevents the hydraulic motor from rotating the turning body in a reverse direction while allowing the hydraulic motor to rotate the turning body in the forward direction,
• wherein the forward direction is opposite to the reverse direction.