Abstract: An engine load control device is adapted to a working vehicle in which output of an engine is transmitted to drive wheels and to hydraulic actuators including a working equipment hydraulic actuator via a plurality of variable capacity hydraulic pumps. The control device includes an engine speed detection unit that detects an engine speed, an instruction content detection unit that detects contents of instructions of a speed instruction device, a hydraulic pump load detection unit that detects load of at least one load detection hydraulic pump among the variable capacity hydraulic pumps, and an absorption torque control unit. The absorption torque control unit controls absorption torque of at least one control hydraulic pump other than the load detection hydraulic pump based on detection results of the engine speed detection unit, the instruction content detection unit, and the hydraulic pump load detection unit.

Abstract: A construction machine capable of increasing a frictional force and an acceleration performance without causing unwanted slip and an excessive load to a transmission by a driving force. The construction machine comprises a first mode to set the maximum output of an engine to a prescribed output, a second mode to limit the maximum output of the engine to an output lower than the prescribed output and a mode selector switch used for a operator to select from the plurality of modes. The construction machine also comprises control means that controls the machine to operate in the second mode regardless of the mode selected by the mode selector switch when a vehicle speed is equal to or less than a prescribed speed and the opening of an accelerator is equal to or more than a prescribed opening.

Abstract: An apparatus for controlling a plurality of hydraulic motors and a clutch is capable of reliably implementing a sequence for engaging and disengaging the clutch and for fixing and clearing a zero tilt rotation amounts of the hydraulic motors, thereby preventing a speed change shock or load slip in the hydraulic motors. The apparatus includes zero tilt rotation fixing means (10A), a clutch (5), hydraulic vehicle speed detecting means (32A), and control valve means (30A) that releases an output command pressure to a return pressure connected to a tank (19) until a vehicle speed signal pressure to be received reaches a start pressure of a predetermined value, and begins to output the command pressure to the zero tilt rotation fixing means and the clutch when the vehicle speed signal pressure exceeds a predetermined value.

Abstract: The invention provides a hydraulically driven vehicle which can reduce a tire slip on a low friction road surface such as a soft road surface, an oversnow road surface or the like and has an excellent work ability in a narrow space. The invention relates to a hydraulically driven vehicle having a hydraulic motor (2) driven by a pressure oil discharged from a hydraulic pump (1) and supplied to the hydraulic motor (2), and traveling by driving the hydraulic motor (2). A maximum driving force of the hydraulic motor (2) is set changeable. The hydraulic motor (2) is a variable displacement hydraulic motor. A maximum driving force is adjusted by electrically controlling a maximum tilt angle of the hydraulic motor (2). A minimum displacement value of the hydraulic motor (2) can be changed by electrically controlling a minimum tilt angle of the hydraulic motor (2).

Abstract: An apparatus for controlling a plurality of hydraulic motors and a clutch is capable of reliably implementing a sequence for engaging and disengaging the clutch and for fixing and clearing a zero tilt rotation amounts of the hydraulic motors, thereby preventing a speed change shock or load slip in the hydraulic motors. The apparatus includes zero tilt rotation fixing means (10A), a clutch (5), hydraulic vehicle speed detecting means (32A), and control valve means (30A) that releases an output command pressure to a return pressure connected to a tank (19) until a vehicle speed signal pressure to be received reaches a start pressure of a predetermined value, and begins to output the command pressure to the zero tilt rotation fixing means and the clutch when the vehicle speed signal pressure exceeds a predetermined value.

Abstract: An apparatus for controlling a plurality of hydraulic motors and a clutch is capable of reliably implementing a sequence for engaging and disengaging the clutch and for fixing and clearing a zero tilt rotation amounts of the hydraulic motors, thereby preventing a speed change shock or load slip in the hydraulic motors. The apparatus includes zero tilt rotation fixing means (10A), a clutch (5), hydraulic vehicle speed detecting means (32A), and control valve means (30A) that releases an output command pressure to a return pressure connected to a tank (19) until a vehicle speed signal pressure to be received reaches a start pressure of a predetermined value, and begins to output the command pressure to the zero tilt rotation fixing means and the clutch when the vehicle speed signal pressure exceeds a predetermined value.

Abstract: The invention provides a hydraulic drive apparatus which obtain a desired speed reduction ratio and a reduced shock during clutch engagement. Accordingly, the hydraulic drive apparatus for a working machine has a variable capacity type first (8) and second hydraulic motor (11), a first input shaft (5) and a second input shaft connected respectively (7). The hydraulic drive apparatus transmits a torque from the first and the second hydraulic motor to an output shaft (2). A planetary gear (21) is interposed between the second hydraulic motor and the second input shaft, and a clutch (10) freely engaging the second hydraulic motor with the second input shaft is provided between a ring gear (29) of the planetary gear and a housing (24). A modulation damper (22) for reducing a clutch pressure (P3) before the engagement and reducing at a time of engagement is provided.

Abstract: A travel assisting hydraulic circuit for a hydraulic drive type working vehicle with enhanced general versatility, in which the traveling assisting circuit during travel at a high speed can be configured to be a simple circuit. For this purpose, in a hydraulic drive type working vehicle including a traveling HST circuit having a traveling pump driven by the power of an engine, and a traveling motor driven by the pressurized oil from the traveling pump, in which the output torque of the traveling motor is transmitted to a drive wheel via a speed reducer, the traveling assisting hydraulic circuit includes an assisting pump driven by the power of the engine, and an assisting motor for outputting the torque generated by being driven by the pressurized oil from the assisting pump to the speed reducer to add the torque to the output torque of the traveling motor.

Abstract: An apparatus for controlling a plurality of hydraulic motors and a clutch is capable of reliably implementing a sequence for engaging and disengaging the clutch and for fixing and clearing a zero tilt rotation amounts of the hydraulic motors, thereby preventing a speed change shock or load slip in the hydraulic motors. The apparatus includes zero tilt rotation fixing means (10A), a clutch (5), hydraulic vehicle speed detecting means (32A), and control valve means (30A) that releases an output command pressure to a return pressure connected to a tank (19) until a vehicle speed signal pressure to be received reaches a start pressure of a predetermined value, and begins to output the command pressure to the zero tilt rotation fixing means and the clutch when the vehicle speed signal pressure exceeds a predetermined value.

Abstract: An apparatus, for controlling a plurality of hydraulic motors and a clutch for driving a drive shaft, can prevent a speed change shock and a load slip of a hydraulic motor as well as making a structure simple. The apparatus includes: a first volume variable hydraulic motor (1), connected to the drive shaft (3) through the clutch (5); a second volume variable hydraulic motor (2), which is always connected to the drive shaft (3); first tilt rotation control means (7, 8), for controlling a tilt rotation amount (a discharge volume cc/rev) of the first hydraulic motor by receiving a drive side pressurized oil (Pac) of the first hydraulic motor; and a zero tilt rotation holding means (10, 10A), for holding the tilt rotation amount of the first hydraulic motor at substantially zero in a state wherein the tilt rotation amount of the first hydraulic motor is controlled to be substantially zero.

Abstract: A hydraulic drive type working vehicle, with speedy responsiveness in an excavating operation, includes: a pouring changeover valve (10), which is switchable between (a) a pouring position, wherein pressurized oil of a travel hydraulic circuit (5) is poured into a working machine hydraulic circuit (8), and (b) a shutoff position, wherein the travel hydraulic circuit (5) and the working machine hydraulic circuit (8) are isolated from each other; a first changeover valve (16), which is switchable from its shutoff position to its communicating position when the oil pressure of the travel hydraulic circuit (5) exceeds a predetermined oil pressure; a pouring command switch (14); and a second changeover valve (17), which is connected in series with the first changeover valve (16) and which is switchable from its shutoff position to its communicating position upon receipt of a pouring command from the pouring command switch (14); and wherein the pouring changeover valve (10) is switchable to the pouring position whe