Patent attributes
A working machine includes a prime mover, a traveling pump configured to deliver hydraulic fluid at a flow rate corresponding to an angle of the swashplate, a traveling motor configured to be rotated by the hydraulic fluid delivered from the traveling pump so as to have a rotation speed shiftable between a first speed and a second speed higher than the first speed, a traveling change-over valve shiftable between a first state to set the rotation speed of the traveling motor to the first speed and a second state to set the rotation speed of the traveling motor to the second speed, an operation device, an operation valve configured to change the angle of the swashplate of the traveling pump according to operation of the operation device, an actuation valve provided upstream or downstream of the operation valve and fluidly connected to the operation valve, and a controller configured or programmed to output a control signal to control the actuation valve in such a way that, when the traveling change-over valve is shifted from the second state to the first state, a value of the control signal is reduced from a set value to a mitigation value less than the set value and then restores to the set value. The controller is configured or programmed to reduce the value of the control signal from the set value to the mitigation value for a mitigation period in such a way that a first reduction rate that is a rate of reducing the value of the control signal for a first part of the mitigation period between a start point thereof and an intermediate point thereof larger than a second reduction rate that is a rate of reducing the value of the control signal for a second part of the mitigation period between the intermediate point thereof and an end point thereof.
