Abstract: A working machine includes a prime mover, a traveling device, a traveling motor, a traveling pump, a circulation fluid passage, a traveling switching valve shiftable between a first state corresponding to a first speed of a hydraulic motor and a second state corresponding to a second speed of the hydraulic motor, a brake, an actuation valve configured to output the hydraulic pressure applied to the traveling pump, and change the hydraulic pressure output therefrom, and a controller configured or programmed to control the traveling switching valve, the brake and the actuation valve, and being capable of activating a first mode. The controller is configured or programmed to, when activating the first mode, shift the brake into a braking state, shift the traveling switching valve into the second state, and control the actuation valve so as to set the hydraulic pressure output from the actuation valve to a predetermined pressure.

Abstract: A working machine includes a controller to perform automatic deceleration to automatically reduce a first rotation speed of a left traveling motor to output a power to a left traveling device on a left portion of a machine body and a second rotation speed of a right traveling motor to output a power to a right traveling device on a right portion of the machine body by shifting a speed stage of each of the left and right traveling motors from a second speed to a first speed that is lower than the second speed. The controller is configured or programmed to determine, based on the second rotation speed, a left threshold for judging whether to perform the automatic deceleration in left pivot turn of the machine body, and to determine, based on the first rotation speed, a right threshold for judging whether to perform the automatic deceleration in right pivot turn of the machine body.

Abstract: A working machine includes a first traveling fluid passage connected to a first pressure-receiving portion, a second traveling fluid passage connected to a second pressure-receiving portion, a third traveling fluid passage connected to a third pressure-receiving portion, a fourth traveling fluid passage fluidly connected to a fourth pressure-receiving portion, and a connection fluid passage connecting at least two of the first, second, third and fourth pressure-receiving portions to each other. When a traveling operation member is operated, operation fluid flows to the first pressure receiving portion through the first traveling fluid passage, to the second pressure receiving portion through the second traveling fluid passage, to the third pressure receiving portion through the third traveling fluid passage, and to the fourth pressure receiving portion through the fourth traveling fluid passage.

Abstract: A control method for a fan of a work vehicle includes supplying, when an engine is started, a first current to a solenoid of a variable relief valve such that the hydraulic fluid flows by a first flow rate, supplying, when a rotational speed of the engine becomes larger than a first rotational speed threshold value, a second current larger than the first current to the solenoid such that the hydraulic fluid flows by a second flow rate smaller than the first flow rate to reduce the rotational speed of the fan, and supplying, when the rotational speed of the engine becomes larger than a second rotational speed threshold value that is larger than the first rotational speed threshold value, a current to the solenoid to change the rotational speed of the fan, the current corresponding to a temperature of liquid flowing in the work vehicle.

Abstract: A working machine includes a controller configured to determine a first deceleration threshold corresponding to each of a first traveling pressure, a second traveling pressure, a third traveling pressure, and a fourth traveling pressure, to perform automatic deceleration to reduce rotation speeds of a left traveling motor and a right traveling motor, and to judge whether to perform the automatic deceleration based on the determined first deceleration threshold, the first traveling pressure, the second traveling pressure, the third traveling pressure, and the fourth traveling pressure.

Abstract: A hydraulic system for a working machine includes hydraulic actuators actuated with hydraulic fluid delivered from a hydraulic pump, control valves each of which is shiftable among shift positions to control a flowrate of hydraulic fluid flowing to the corresponding hydraulic actuator, a detection fluid passage, an interlocking control valve, and a pressure detection unit. Each control valve includes an input port, an output port, and a flowrate reduction section. One of the control valves includes a flowrate increase section. The interlocking control valve is configured to be shifted in accordance with a shift of the one of the control valves among the shift positions and to be shifted to a blocking position to block a pilot fluid introduced into the interlocking control valve from the detection fluid passage when the one of the control valves is shifted to the increase position.

Abstract: A hydraulic system for a working vehicle includes a first hydraulic pump to deliver pilot fluid to a control valve for a hydraulic actuator whose highest load pressure acts on a first fluid passage, and a second hydraulic pump to deliver hydraulic fluid whose pressure acts on a second fluid passage. A hydraulic controller is operable to control a load-sensing (LS) differential pressure between the highest load pressure and a delivery pressure of the hydraulic fluid from the second hydraulic pump. A third fluid passage to which the second hydraulic pump delivers the hydraulic fluid branches to a fourth fluid passage for flow of the pilot fluid. A solenoid valve is operable to change a pilot pressure of the pilot fluid for the hydraulic controller, and a controller is configured or programmed to control the solenoid valve to adjust the pilot pressure to change the LS differential pressure.

Abstract: A working machine is provided, which includes a machine body, a prime mover, a pair of traveling devices, a pair of traveling motors to be switched between a first speed and a second speed higher than the first speed, a pair of traveling pumps driven by the prime mover to supply operation fluid to the pair of traveling motors, respectively, a controller configured to automatically shift down the pair of traveling motors from the second speed to the first speed, a mode switch configured for an operator to select an ON position allowing the controller to automatically shift down the first traveling motor from the second speed to the first speed and an OFF position preventing the controller to automatically shift down the first traveling motor from the second speed to the first speed, and a display to display that the operator selects the ON position of the mode switch.

Abstract: A working machine includes a prime mover, a traveling motor a speed shifting valve configured to shift an output speed of the traveling motor between a first speed and a second speed faster than the first speed, an actuation valve to change a hydraulic pressure applied to the speed shifting valve, a brake shiftable between a braking state to brake the traveling motor and a braking releasing state to release the braking, and a controller configured or programmed to control the actuation valve and the brake, and being capable of activate a warm-up mode. The controller, when activating the warm-up mode, shifts the brake into the braking state, and controls the actuation valve so as to make the hydraulic pressure applied to the speed shifting valve equal to or greater than a value corresponding to the second speed.

Abstract: A working machine includes a prime mover, a traveling pump driven by a power of the prime mover to deliver operation fluid, a traveling motor rotated by the operation fluid delivered from the traveling pump to have a rotation speed stage shiftable between a first speed stage and a second speed stage higher than the first speed stage, a traveling switching valve shiftable between a first state where the rotation speed stage of the traveling motor is set to the first speed stage and a second state where the rotation speed stage of the traveling motor is set to the second speed stage, an actuation valve configured to change a pilot pressure of a pilot fluid to control a flow of operation fluid delivered from the traveling pump, and a controller configured to control the pilot pressure of the pilot fluid output from the actuation valve so that a value of the pilot pressure differs depending on whether the set rotation speed stage of the traveling motor is the first speed stage or the second speed stage.

Abstract: A working machine includes a prime mover, a hydraulic pump driven by power of the prime mover, a cooler including a cooling fan rotated by either the power of the prime mover or hydraulic fluid delivered from the hydraulic pump, and a controller configured or programmed to perform a reduction control for reducing a target fan rotation speed that is a target rotation speed of the cooling fan in response to reduction of an actual prime mover rotation speed that is an actual rotation speed of the prime mover, and to perform, after the reduction control, a restoration control for restoring the target fan rotation speed. The controller is configured or programmed to make a difference between a reduction rate of the target fan rotation speed in the reduction control and an increase rate of the target fan rotation speed in the restoration control.

Abstract: A hydraulic system for a working machine includes a traveling motor to output power to a traveling device in the working machine, a first detector to detect a physical quantity that changes in accordance with a traveling state of the working machine and that is detected at intervals of a predetermined period, and a controller to execute automatic shift-down to automatically reduce a rotational speed of the traveling motor to a first speed stage when the rotational speed of the traveling motor is in a second speed stage higher than the first speed stage. The controller is configured or programmed to determine a tendency or degree of change in the physical quantity, based on values of the physical quantity detected at intervals of the predetermined period by the first detector.

Abstract: A control valve of hydraulic system for a working machine is provided, which includes a main body and a spool. The main body includes first, second, third, fourth and fifth ports, and first second, third, fourth and fifth inner fluid paths connected to the first, second, third, fourth and fifth ports, respectively. The spool is configured to move between a neutral position and a communicating position allowing fluid communication between the second inner fluid path and the fifth inner fluid path or between the first inner fluid path and the fifth inner fluid path. The spool includes a communicating hole configured to allow the fluid communication between the second port and the fourth port, or between the first port and the fourth port, when the spool is in a position between the communicating position and the neutral position.

Abstract: A working machine is provided, which includes a prime mover, a first traveling pump driven by power of the prime mover to supply operation fluid through a connector fluid tube, a traveling motor including first and second ports connected to the connector fluid tube, the traveling motor configured to be switched in a first speed and a second speed higher than the first speed, a first pressure detector to detect first traveling-pump pressure near the first port, a second pressure detector to detect second traveling-pump pressure near the second port, and a controller configured, with the traveling motor switched in the second speed, to automatically shift down the traveling motor from the second speed to the first speed, when a differential pressure between the first traveling-pump pressure and the second traveling-pump is equal to or more than a deceleration threshold.

Abstract: A working machine includes a machine body, a traveling device, a traveling motor configured to provide power to the traveling device and to be switched between a first speed and a second speed higher than the first speed, a traveling operation member, an operation detector to detect an operation extent of the traveling operation member, a traveling pump driven in response to the operation extent, a revolution detector to detect a motor revolving speed of the traveling motor, and a controller configured, with the traveling operation member maintained at a predetermined operation extent, to switch the traveling motor from the second speed to the first speed when the motor revolving speed is equal to or less than a deceleration threshold which is less than a first top or maximum revolving speed of the traveling motor switched to the first speed, for the predetermined operation extent.

Abstract: In a hydraulic system for a working machine, a controller is configured or programmed to increase an output-port pressure of one activation valve for one hydraulic device and an output-port pressure of another activation valve for another hydraulic device to a normal pressure higher than a preloading pressure from a state where the output-port pressure of the one activation valve is equal to the preloading pressure and the output-port pressure of the other activation valve is lower than the preloading pressure, by causing the output-port pressure of the one activation valve to be lower than the preloading pressure and increasing the output-port pressure of the other activation valve to the normal pressure.

Abstract: A hydraulic system of a working machine includes a hydraulic pump to output a hydraulic fluid, at least one proportional valve to deliver the hydraulic fluid to a supply target, a valve body including the proportional valve, a heat-up fluid passage in the valve body and into which the hydraulic fluid flows, a switching valve switchable between an open position in which the hydraulic fluid passing through the heat-up fluid passage is supplied to a hydraulic device and a closed position in which the hydraulic fluid is not supplied thereto and the hydraulic fluid from the hydraulic device is to be returned, a controller to operate the switching and proportional valves, and a return circuit through which the hydraulic fluid flowing into the heat-up fluid passage is returned as a result of at least one of the switching and proportional valves being operated by the controller.

Abstract: A hydraulic system includes: a boom cylinder to move a boom; a working tool cylinder to move a working tool attached to the boom; a boom control valve to control the boom cylinder; a working tool control valve to control the working tool cylinder; a horizontal control valve having: an activating position to allow a horizontalizing operation of the working tool; and a stopping position to stop the horizontalizing operation; and a controller device having: a first information obtaining portion to obtain permission and non-permission to the horizontalizing operation; a second information obtaining portion to obtain at least one of upward operation and upward movement of the boom; and a horizontal controller to set the horizontal control valve to the stopping position when the first information obtaining portion obtains the non-permission and the second information obtaining portion obtains one of the upward operation and the upward movement.

Abstract: A working machine includes a machine body, a traveling device provided on the machine body, a traveling motor configured to provide power to the traveling device and to be switched between a first speed and a second speed, a traveling operation member to be operated by an operator, an operation detector to detect an operation extent of the traveling operation member, a traveling pump driven in response to the operation extent to supply operation fluid to the traveling motor, a revolution detector to detect a motor revolving speed, and a controller configured to switch the traveling motor from the second speed to the first speed when the motor revolving speed is equal to or less than a deceleration threshold, and then to switch the traveling motor from the first speed to the second speed when the motor revolving speed is equal to or greater than a return threshold.

Abstract: A control method for a fan of a work vehicle includes supplying, when an engine is started, a first current to a solenoid of a variable relief valve such that the hydraulic fluid flows by a first flow rate, supplying, when a rotational speed of the engine becomes larger than a first rotational speed threshold value, a second current larger than the first current to the solenoid such that the hydraulic fluid flows by a second flow rate smaller than the first flow rate to reduce the rotational speed of the fan, and supplying, when the rotational speed of the engine becomes larger than a second rotational speed threshold value that is larger than the first rotational speed threshold value, a current to the solenoid to change the rotational speed of the fan, the current corresponding to a temperature of liquid flowing in the work vehicle.