Abstract: There are provided: a first circuit for traveling HC1, formed through a closed circuit connection of a variable displacement hydraulic pump 2 and a variable displacement hydraulic motor 3, that includes a motor control unit 10, 11 that controls a displacement of the hydraulic motor 3; a second circuit for working HC2 that drives a work hydraulic actuator 114, 115 by pressure oil from a work hydraulic pump 4; and a maximum value control unit that controls a maximum displacement of the hydraulic motor 3 in accordance with load pressure Pf in the second circuit HC2. The maximum value control unit decreases the maximum displacement to a minimum limit q1 corresponding to a maximum load pressure Pr in the second circuit when load pressure Pf in the second circuit exceeds a predetermined value Ps.

Abstract: A control apparatus for a working vehicle includes a travel circuit HC1 formed through a closed circuit connection of a variable displacement hydraulic pump driven by an engine and a variable displacement hydraulic motor, a work circuit HC2 that includes a work hydraulic pump driven by the engine and a work hydraulic actuator that operates by pressure oil from the work hydraulic pump, a relief valve that relieves high pressure oil of the travel circuit HC1, a rotation speed control unit that controls the engine rotation speed in correspondence to an accelerator pedal operation amount, a state detection unit that detects a vehicle state of high load travel and high load work, and a speed limitation unit that reduces an engine rotation speed upper limit when the vehicle state of high load travel and high load work is detected.

Abstract: There are provided: a pedal operation amount detection unit 12 that detects an operation amount s of the accelerator pedal 11; a speed ratio detection unit 14, 15 that detects a speed ratio e of an input shaft and an output shaft of the torque converter 2; a load pressure detection unit 16 that detects a load pressure P of the hydraulic pump 6; a speed stage detection unit 18 that detects a low speed stage of a transmission 3 capable of varying a speed stage between a low speed stage and a high speed stage; and a speed limiting unit 10 that limits a maximum speed of the engine 1 to a lower speed upon satisfaction of following speed limitation conditions: at least a pedal operation amount s is equal to or greater than a predetermined value s1, a speed ratio e is equal to or less than a predetermined value ea, a load pressure P is equal to or greater than a predetermined value Pa, and the low speed stage of the transmission has been detected.

Abstract: A first motor 3 and a second motor 4 of variable displacement type are in parallel to each other connected to a hydraulic pump 2 in a closed circuit, through which the output torque from the first motor 3 is transmitted to an output shaft 6. A clutch control unit 10 controls a clutch device 15 as: when the engine speed is N1, which is the case where the accelerator pedal is fully depressed, the clutch is disengaged at the vehicle speed v1. When the engine speed is N3(<N1), which is the case where the accelerator pedal is half depressed, the clutch is disengaged at the vehicle speed v3(<v1).

Abstract: A first motor 3 and a second motor 4 of variable displacement type are in parallel to each other connected to a hydraulic pump 2 in a closed circuit, through which the output torque from the first motor 3 is transmitted to an output shaft 6. A clutch control unit 10 controls a clutch device 15 as: when the engine speed is N1, which is the case where the accelerator pedal is fully depressed, the clutch is disengaged at the vehicle speed v1. When the engine speed is N3(<N1), which is the case where the accelerator pedal is half depressed, the clutch is disengaged at the vehicle speed v3(<v1).

Abstract: There are provided: a pedal operation amount detection unit 12 that detects an operation amount s of the accelerator pedal 11; a speed ratio detection unit 14, 15 that detects a speed ratio e of an input shaft and an output shaft of the torque converter 2; a load pressure detection unit 16 that detects a load pressure P of the hydraulic pump 6; a speed stage detection unit 18 that detects a low speed stage of a transmission 3 capable of varying a speed stage between a low speed stage and a high speed stage; and a speed limiting unit 10 that limits a maximum speed of the engine 1 to a lower speed upon satisfaction of following speed limitation conditions: at least a pedal operation amount s is equal to or greater than a predetermined value s1, a speed ratio e is equal to or less than a predetermined value ea, a load pressure P is equal to or greater than a predetermined value Pa, and the low speed stage of the transmission has been detected.

Abstract: There are provided: a first circuit for traveling HC1, formed through a closed circuit connection of a variable displacement hydraulic pump 2 and a variable displacement hydraulic motor 3, that includes a motor control unit 10, 11 that controls a displacement of the hydraulic motor 3; a second circuit for working HC2 that drives a work hydraulic actuator 114, 115 by pressure oil from a work hydraulic pump 4; and a maximum value control unit 10 that controls a maximum displacement of the hydraulic motor 3 in accordance with load pressure Pf in the second circuit HC2. The maximum value control unit 10 decreases the maximum displacement to a minimum limit q1 corresponding to a maximum load pressure Pr in the second circuit when load pressure Pf in the second circuit exceeds a predetermined value Ps.

Abstract: There are provided: a travel circuit HC1 that is formed through a closed circuit connection of a variable displacement hydraulic pump 2 driven by an engine 1 and a variable displacement hydraulic motor 3; a work circuit HC2 that includes a work hydraulic pump 4 that is driven by the engine 1 and a work hydraulic actuator 114, 115 that operates by pressure oil from the work hydraulic pump 4; a relief valve 14 that relieves high pressure oil of the travel circuit HC1; a rotation speed control unit 10, 18 that controls the engine rotation speed in correspondence to an operation amount of an accelerator pedal 9; a state detection unit 21, 22 that detects a vehicle state of high load travel and high load work; and a speed limitation unit 10 that reduces an upper limit of engine rotation speed when the vehicle state of high load travel and high load work is detected by the state detection unit 21, 22.