Abstract: A loading vehicle is capable of improving work efficiency by adjusting engine rotational speed with high accuracy in accordance with an operation state of the working device. An HST traveling driven wheel loader has an electrically controlled HST pump. A controller is configured to control input torque of the HST pump 31 and solenoid proportional pressure reducing valve is configured to generate control pressure for controlling displacement volume of the pump based on a control signal from the controller. The controller is configured to calculate the displacement volume q of the HST pump based on discharge pressure Pf of a loading hydraulic pump so that maximum input torque Thst of the HST pump decreases as the discharge pressure Pf or input torque of the loading hydraulic pump increases, and output a control signal corresponding to the calculated displacement volume q to the solenoid proportional pressure reducing valve.

Abstract: Provided is a working vehicle capable of increasing lifting operation speed of a working device without increasing cost, even when provided with a circuit configuration that prioritizes a steering operation over a working device operation. A wheel loader 1 comprises a priority valve 451 configured to allow hydraulic oil discharged from a hydraulic pump 41 to flow into a steering drive circuit 43 preferentially over a working device drive circuit 44, and further comprises: an electric steering lever 30; a pair of solenoid control valves 34A, 34B configured to control a steering directional control valve 33; and a controller 5. The controller 5 is configured to control the pair of solenoid control valves 34A, 34B so as to limit operation speed of a steering 3 when determining that an engine 40 is in a low idle state and a lift arm 21 is performing a lifting operation.

Abstract: A wheel loader configured to reduce the traveling distance required for a raise and run operation, and reduce fuel consumption includes: an engine 3; a torque converter 41; a forward and reverse switch 62; a stepping amount sensor 610; an operation amount sensor 73; and a controller 5. The controller 5 determines whether a specific condition for specifying an operation of the lift arm 21 in an upper direction during forward travel of the vehicle body, on the basis of a forward and reverse switching signal, the stepping amount on the accelerator pedal 61, and a pilot pressure Ti pertaining to the lifting operation amount for the lift arm 21. When the specific condition is satisfied, the vehicle speed is limited by reducing the maximum rotational speed of the engine 3 in response to increase in the pilot pressure Ti.

Abstract: Provided is a work vehicle capable of attaining a maximum vehicle speed specification value set in advance for each vehicle body even in the case where a device constituting an HST traveling drive system has deteriorated over time. In a wheel loader 1 equipped with an HST traveling drive system, a controller 5 is configured to, in the case where a detection pressure value P is equal to or less than a switching pressure value Ps corresponding to a switching point in the HST motor 42 between a maximum displacement volume qmax and a minimum displacement volume qmin, and a detection vehicle speed value V is less than an upper limit vehicle speed specification value Vmaxs, limit the minimum displacement volume qmin of the HST motor 42 to a first minimum displacement volume value qmin1 less than a minimum displacement volume specification value qmins that is associated with the upper limit vehicle speed specification value Vmaxs.

Abstract: Provided is a work machine capable of notifying that maintenance is necessary due to continuation of clogging in a cooling device or decrease in cooling performance. A wheel loader 1 including a radiator 31 and an oil cooler 32 comprises a controller 5, 5A configured to determine a clogging continuation state of the radiator 31 or the oil cooler 32. The controller 5, 5A determines whether clogging is occurring in the radiator 31 or the oil cooler 32 based on outside air temperature AW and cooling water temperature CW or hydraulic oil temperature HW, determines whether the clogging continues based on a clogging occurrence ratio R1, R2 while an engine 30 is operating, and outputs a notification command signal for providing the alarm buzzer 61 and the user management system 62 with a command to notify that maintenance is necessary when it is determined that the clogging continues.

Abstract: A wheel loader is provided that can suppress abrupt change in vehicle speed accompanied by erroneous determination on a lift arm lifting operation. A wheel loader includes: an engine; an HST pump; an HST motor; a forward and reverse switch; a stepping amount sensor; an operation amount sensor; and a controller. The controller determines whether a specific condition for specifying an operation of the lift arm in an upper direction during forward travel of the vehicle body, on the basis of a forward and reverse switching signal, the stepping amount, and a pilot pressure pertaining to the lifting operation for the lift arm. In a case of the specific condition being satisfied, the vehicle speed is limited by controlling the displacement volume of the HST motor in conformity with increase in the pilot pressure.

Abstract: Provided is a wheel loader capable of moving up a lift arm in a short time during excavation work. A wheel loader comprises a controller configured to control maximum traction force of the wheel loader and input torque of a working device hydraulic pump, and include a specific condition determination section configured to determine whether a specific condition for specifying excavation work is satisfied, an elapsed time measurement section configured to measure an elapsed time from start of the excavation work, and an input torque control section configured to limit the input torque to a first input torque value when the specific condition is satisfied and increase the input torque from the first input torque value when a second set time elapses from the elapse of a first set time.

Abstract: Provided is a loading vehicle in which a control characteristic of traction force can be easily and finely set and changed while a configuration of a hydraulic circuit is simple. An HST traveling driven wheel loader includes an electronically controlled HST pump and HST motor, including a solenoid proportional pressure reducing valve to control displacement volume of the HST pump based on a control signal output from a controller. The controller stores characteristic tables indicating a correlation between discharge pressure of a loading hydraulic pump or an operation state of an engine and a maximum discharge pressure of the HST pump, and when the vehicle speed corresponds to work requiring traction force, outputs a control signal to the solenoid proportional pressure reducing valve so as to obtain the maximum discharge pressure Pm of the HST pump that corresponds to one of the characteristic tables.

Abstract: To curb temperature rises in a control device for a supercharger and extend the life of the control device for the supercharger, a work vehicle includes a variable geometry supercharger with variable boost pressure, and a working device driven by pressure oil discharged from a working hydraulic pump, the work vehicle further including: a supercharger control device adapted to control the supercharger; a temperature detection device adapted to detect temperature of the supercharger control device; and a main control device adapted to limit at least one of maximum rotational speed of an engine and maximum vehicle speed of the work vehicle in case the temperature of the supercharger control device is above a predetermined temperature as compared to case the temperature of the supercharger control device is below the predetermined temperature.

Abstract: A wheel loader configured to reduce a sudden change in vehicle speed caused by an erroneous determination of a raising operation of a lift arm is provided. A wheel loader 1 includes an engine 3, a variable displacement type HST pump 41, a variable displacement type HST motor 42 coupled to the HST pump 41 in a closed circuit, a hydraulic pump for working device 43, a forward/reverse selector switch 62 for switching a forward movement and a backward movement of a vehicle body, a depression amount sensor 610 that detects a depression amount of an accelerator pedal 61, a pressure sensor 73 that detects a discharge pressure Pa of the hydraulic pump for working device 43, and a controller 5. The controller 5 determines whether a specific condition to identify an upward movement of a lift arm 21 during a forward travel of the vehicle body based on a forward/reverse switching signal, the depression amount of the accelerator pedal 61, and the discharge pressure Pa detected by the pressure sensor 73.

Abstract: A work vehicle is provided. The work vehicle is capable of notifying an operator of a state close to overheating of a temperature of a cooling oil that cools a brake device before the temperature overheats. A controller (10) in a work vehicle (100) compares each detection value detected from a brake pressure sensor (26) and a vehicle speed sensor (15) to each threshold (V1, P1, R1) predetermined corresponding to each sensor. The controller (10) outputs a warning command that a temperature of a cooling oil is likely to overheat to a notification device (28) when a state that at least one detection value is equal to or more than the threshold and when a state that at least one detection value is equal to or more than the threshold continues for a first duration (t1) or more.

Abstract: A wheel loader configured to reduce a sudden change in vehicle speed caused by an erroneous determination of a raising operation of a lift arm is provided. A wheel loader 1 includes an engine 3, a variable displacement type HST pump 41, a variable displacement type HST motor 42 coupled to the HST pump 41 in a closed circuit, a hydraulic pump for working device 43, a forward/reverse selector switch 62 for switching a forward movement and a backward movement of a vehicle body, a depression amount sensor 610 that detects a depression amount of an accelerator pedal 61, a pressure sensor 73 that detects a discharge pressure Pa of the hydraulic pump for working device 43, and a controller 5. The controller 5 determines whether a specific condition to identify an upward movement of a lift arm 21 during a forward travel of the vehicle body based on a forward/reverse switching signal, the depression amount of the accelerator pedal 61, and the discharge pressure Pa detected by the pressure sensor 73.

Abstract: Provided is a work machine capable of notifying that maintenance is necessary due to continuation of clogging in a cooling device or decrease in cooling performance. A wheel loader 1 including a radiator 31 and an oil cooler 32 comprises a controller 5, 5A configured to determine a clogging continuation state of the radiator 31 or the oil cooler 32. The controller 5, 5A determines whether clogging is occurring in the radiator 31 or the oil cooler 32 based on outside air temperature AW and cooling water temperature CW or hydraulic oil temperature HW, determines whether the clogging continues based on a clogging occurrence ratio R1, R2 while an engine 30 is operating, and outputs a notification command signal for providing the alarm buzzer 61 and the user management system 62 with a command to notify that maintenance is necessary when it is determined that the clogging continues.

Abstract: Provided is a loading vehicle in which a control characteristic of traction force can be easily and finely set and changed while a configuration of a hydraulic circuit is simple. An HST traveling driven wheel loader includes an electronically controlled HST pump and HST motor, including a solenoid proportional pressure reducing valve to control displacement volume of the HST pump based on a control signal output from a controller. The controller stores characteristic tables indicating a correlation between discharge pressure of a loading hydraulic pump or an operation state of an engine and a maximum discharge pressure of the HST pump, and when the vehicle speed corresponds to work requiring traction force, outputs a control signal to the solenoid proportional pressure reducing valve so as to obtain the maximum discharge pressure Pm of the HST pump that corresponds to one of the characteristic tables.

Abstract: Provided is a loading work vehicle capable of improving work efficiency even when working on a slippery road surface. An HST-traveling-drive wheel loader 1 comprises a step-on amount detection sensor 610, a discharge pressure detection sensor 75, a mode switch device 60, and a controller 5. The controller 5 is configured to: determine whether a limit mode is selected by the mode switch device 60; specify an operation state of the wheel loader 1 when determining that the limit mode is selected; limit maximum traction force to a first set value which is set based on a static friction coefficient ? and vehicle weight when specifying that a bucket 23 is pushed into a natural ground 100; and increase the maximum traction force from the first set value when specifying that excavation of the natural ground 100 is started.

Abstract: A loading vehicle is capable of improving work efficiency by adjusting engine rotational speed with high accuracy in accordance with an operation state of the working device. An HST traveling driven wheel loader has an electrically controlled HST pump. A controller is configured to control input torque of the HST pump 31 and solenoid proportional pressure reducing valve is configured to generate control pressure for controlling displacement volume of the pump based on a control signal from the controller. The controller is configured to calculate the displacement volume q of the HST pump based on discharge pressure Pf of a loading hydraulic pump so that maximum input torque Thst of the HST pump decreases as the discharge pressure Pf or input torque of the loading hydraulic pump increases, and output a control signal corresponding to the calculated displacement volume q to the solenoid proportional pressure reducing valve.

Abstract: Provided is a working vehicle capable of, while reducing fuel consumption, improving traveling performance only when high traveling performance is required. A wheel loader 1 comprises: an engine 3; a variable displacement HST pump 41; a variable displacement HST motor 42 connected to the HST pump 41 through a closed circuit; pressure sensors 72A, 72B configured to load pressure of the HST motor 42; and a controller 5, wherein the controller 5 is configured to, in a case of determining that a load pressure detection value P is included in a predetermined pressure range of greater than load pressure P? corresponding to flat ground traveling and smaller than load pressure P? corresponding to an excavation operation, increase maximum rotational speed of the engine 3 only within the predetermined pressure range.

Abstract: Provided is a working vehicle capable of increasing lifting operation speed of a working device without increasing cost, even when provided with a circuit configuration that prioritizes a steering operation over a working device operation. A wheel loader 1 comprises a priority valve 451 configured to allow hydraulic oil discharged from a hydraulic pump 41 to flow into a steering drive circuit 43 preferentially over a working device drive circuit 44, and further comprises: an electric steering lever 30; a pair of solenoid control valves 34A, 34B configured to control a steering directional control valve 33; and a controller 5. The controller 5 is configured to control the pair of solenoid control valves 34A, 34B so as to limit operation speed of a steering 3 when determining that an engine 40 is in a low idle state and a lift arm 21 is performing a lifting operation.

Abstract: Provide is a loading vehicle capable of quickly operating an object handling device in the upward direction while traveling forward. A wheel loader 1 comprises an engine 3, an HST pump 41, an HST motor 42, a forward/reverse changeover switch 62, a step-on amount sensor 610, a pressure sensor 73, and a controller 5. In a case where a specific condition for specifying lifting operation of a lift arm 21 during forward traveling of the vehicle body is satisfied, the controller 5 increases maximum rotational speed of the engine to a predetermined value Nmax2 which is greater than maximum engine rotational speed Nmax1 during traveling on the flat ground, and limit maximum vehicle speed to a predetermined value Vmax2 which is smaller than maximum vehicle speed Vmax1 prior to the lifting operation of the lift arm 2.

Abstract: Provided is a working vehicle capable of, while reducing fuel consumption, improving traveling performance only when high traveling performance is required. A wheel loader 1 comprises: an engine 3; a variable displacement HST pump 41; a variable displacement HST motor 42 connected to the HST pump 41 through a closed circuit; pressure sensors 72A, 72B configured to load pressure of the HST motor 42; and a controller 5, wherein the controller 5 is configured to, in a case of determining that a load pressure detection value P is included in a predetermined pressure range of greater than load pressure Pa corresponding to flat ground traveling and smaller than load pressure P? corresponding to an excavation operation, increase maximum rotational speed of the engine 3 only within the predetermined pressure range.