Abstract: In a regenerative braking device of a dump truck comprising an engine, a first generator and a second generator driven by the engine, at least one travel motor driven by generated electric power of the first generator and at least one fan motor to which generated electric power of the second generator is inputted via a first rectifier circuit, the regenerative braking device comprises: a resistive element to which regenerating electric power from the at least one travel motor in regenerative braking is supplied and which is cooled by at least one fan driven by the at least one fan motor and converts electric energy into heat energy and dissipates heat; and a DC/DC converter that inputs a part of the regenerating electric power which is supplied to the resistive element to an output line of the first rectifier circuit via a second rectifier circuit.

Abstract: A hybrid work machine includes: an engine configured to drive a hydraulic pump as a hydraulic source of a hydraulic actuator; an engine-assist motor generator attached to the engine; an electric motor for use in a part of a driving system of the work machine; an electricity storage device configured to store generated power of the motor generator; a power converter disposed between the electric motor and DC buses; and a buck-boost converter disposed between the DC buses and the electricity storage device, and configured to perform power transfer between the DC buses and the electricity storage device by raising and lowering a voltage of the DC buses, the hybrid work machine, further comprises: a controller configured to temporarily raise the voltage of the DC buses when a torque required for the electric motor exceeds a torque outputtable at the voltage of the DC buses connected to the power converter.

Abstract: An object of the present invention is to provide a hybrid working vehicle that enables enhancing efficiency of an engine.

Abstract: A hybrid type work vehicle includes a power source, a traveling unit, a hydraulic work unit, an accelerator pedal, a brake pedal, an operation lever device, and a control apparatus. The control apparatus is configured such that when the current operation state is determined to be that of an excavation work which is a combined operation of the traveling unit and the hydraulic work unit and the output power limitation signal is outputted, the control apparatus limits the output power of the traveling unit. The control apparatus is also configured to decrease the tilting angle of the hydraulic pump, such that a ratio between the output power of the traveling unit and the output power of the hydraulic work unit is maintained at a preset ratio.

Abstract: In a regenerative braking device of a dump truck comprising an engine, a first generator and a second generator driven by the engine, at least one travel motor driven by generated electric power of the first generator and at least one fan motor to which generated electric power of the second generator is inputted via a first rectifier circuit, the regenerative braking device comprises: a resistive element to which regenerating electric power from the at least one travel motor in regenerative braking is supplied and which is cooled by at least one fan driven by the at least one fan motor and converts electric energy into heat energy and dissipates heat; and a DC/DC converter that inputs a part of the regenerating electric power which is supplied to the resistive element to an output line of the first rectifier circuit via a second rectifier circuit.

Abstract: Provided is a working machine capable of regenerating and utilizing surplus energy. The working machine related to the present invention is provided with a branching flow path (150) through which hydraulic oil flows between a hydraulic actuator (24) and a hydraulic pump-motor (14), an accumulator (30) arranged in the branching flow path, a first opening/closing valve (31) arranged between the accumulator and the hydraulic pump-motor, and a second opening/closing valve (32) arranged between the accumulator and the hydraulic actuator. A control device (41) selectively introduces the hydraulic oil from the hydraulic actuator and the hydraulic oil from the hydraulic pump-motor to the accumulator and accumulates the same by controlling opening/closing of the first opening/closing valve and the second opening/closing valve.

Abstract: The hybrid type work vehicle includes: a traveling unit having a traveling electric motor; a hydraulic work unit having a hydraulic pump; and a control apparatus having an operation determination section configured to input the operation amount of an operation lever device, the depression amount of an accelerator pedal and a brake pedal, and a vehicle speed and to determine the current operation state of the vehicle, and a power computation section configured to input the output value of an engine and the output value of a power storage device and to calculate and control the power of the traveling unit and the power of the hydraulic work unit.

Abstract: A hybrid wheel loader includes a control device (200) that estimates output power of an engine (1) and an electricity storage device (11) when the hybrid wheel loader is inferred on the basis of output values of detectors (62, 63) to be traveling towards an object of excavation in order to perform an excavating work, and then, if the output power is less than target power considered necessary for the excavating work, accelerates the engine (1) to a target revolution speed while increasing the electric power supplied from the electricity storage device to a traveling motor (9). Accordingly, power necessary for excavation can be drawn from the engine even when the engine revolution speed is low and there is a fear of power deficiency occurring at the time of the excavating work.

Abstract: Provided is a working machine capable of regenerating and utilizing surplus energy. The working machine related to the present invention is provided with a branching flow path (150) through which hydraulic oil flows between a hydraulic actuator (24) and a hydraulic pump-motor (14), an accumulator (30) arranged in the branching flow path, a first opening/closing valve (31) arranged between the accumulator and the hydraulic pump-motor, and a second opening/closing valve (32) arranged between the accumulator and the hydraulic actuator. A control device (41) selectively introduces the hydraulic oil from the hydraulic actuator and the hydraulic oil from the hydraulic pump-motor to the accumulator and accumulates the same by controlling opening/closing of the first opening/closing valve and the second opening/closing valve.

Abstract: An object of the present invention is to provide a hybrid working vehicle that enables enhancing efficiency of an engine.

Abstract: There are provided a work vehicle comprising a motor generator (6) driven by an engine, a hydraulic pump (4) driven by at least either of the motor generator and the engine, a work device (50) driven by hydraulic fluid from the hydraulic pump, a electric traction motor (9) driving wheels (61), an electrical storage device (11) connected to the motor generator and to the electric traction motor and charged electrically on the basis of a target SOC; and a control device (200) varying the target SOC for the electrical storage device (11) on the basis of total demanded power (Pf+Prun) of the hydraulic pump and the electric traction motor.

Abstract: A hybrid work machine includes: an engine configured to drive a hydraulic pump as a hydraulic source of a hydraulic actuator; an engine-assist motor generator attached to the engine; an electric motor for use in a part of a driving system of the work machine; an electricity storage device configured to store generated power of the motor generator; a power converter disposed between the electric motor and DC buses; and a buck-boost converter disposed between the DC buses and the electricity storage device, and configured to perform power transfer between the DC buses and the electricity storage device by raising and lowering a voltage of the DC buses, the hybrid work machine, further comprises: a controller configured to temporarily raise the voltage of the DC buses when a torque required for the electric motor exceeds a torque outputtable at the voltage of the DC buses connected to the power converter.

Abstract: A hybrid wheel loader includes a control device (200) that estimates output power of an engine (1) and an electricity storage device (11) when the hybrid wheel loader is inferred on the basis of output values of detectors (62, 63) to be traveling towards an object of excavation in order to perform an excavating work, and then, if the output power is less than target power considered necessary for the excavating work, accelerates the engine (1) to a target revolution speed while increasing the electric power supplied from the electricity storage device to a traveling motor (9). Accordingly, power necessary for excavation can be drawn from the engine even when the engine revolution speed is low and there is a fear of power deficiency occurring at the time of the excavating work.

Abstract: An electrically driven working vehicle that requiring reduced power assistance from an electrical storage device is provided. The vehicle has an engine, a generator motor connected to the engine, a generator inverter for controlling the amount of power generated by the generator motor, a traveling motor for driving the vehicle, an electrical storage device connected to the generator inverter and the traveling motor, and a forward/reverse switching device for switching the traveling direction of the vehicle. The vehicle further includes a control device for outputting to the generator inverter an instruction to increase the amount of power generated by the generator motor when the voltage of the electrical storage device is equal to or lower than a maximum voltage level and a speed signal of the traveling motor given upon switching of the forward/reverse switching device is equal to or lower than a predetermined speed.

Abstract: When the total value of demanded hydraulic power and demanded traveling power is larger than the sum of the engine power that can be output by an engine (1) and of the discharge power that can be discharged by an electrical storage device (3), the actual power of a hydraulic pump (9) is increased from the value at the time of demand toward the demanded hydraulic power under the constraint of a predetermined limit. While the power of the hydraulic pump is being subjected to the predetermined limit, the actual power of the traveling motor is decreased from the value at the time of demand by a value smaller than the magnitude of the predetermined limit. This prevents worsening of ride comfort attributable to the distribution of power between the hydraulic pump and the traveling motor.

Abstract: A hybrid wheel loader is provided, the hybrid wheel loader achieving high work efficiency even with a short supply of power to be output relative to a vehicle power requirement. The hybrid wheel loader includes a motor generator 6 connected to an engine (1), a hydraulic pump (4) connected to the motor generator, a hydraulic actuator (51, 52, 53) driven by hydraulic oil supplied from the hydraulic pump, a travel electric motor (9) for driving wheels (61), and an electrical storage device (11) connected to each of the motor generator and the electrical storage device via respective inverters (7, 10). When a total requirement power value is greater than a hybrid output upper limit value, either one of a hydraulic requirement power value Pf and a travel requirement power value Prun is limited according to an operation of the wheel loader to thereby set the total requirement power value to a value equal to, or less than, the hybrid output upper limit value.

Abstract: There are provided a work vehicle comprising a motor generator (6) driven by an engine, a hydraulic pump (4) driven by at least either of the motor generator and the engine, a work device (50) driven by hydraulic fluid from the hydraulic pump, a electric traction motor (9) driving wheels (61), an electrical storage device (11) connected to the motor generator and to the electric traction motor and charged electrically on the basis of a target SOC; and a control device (200) varying the target SOC for the electrical storage device (11) on the basis of total demanded power (Pf+Prun) of the hydraulic pump and the electric traction motor.

Abstract: [Problem] To provide a hybrid work vehicle which is simple in configuration, good in ease of mounting on a vehicle and capable of efficiently transmitting motive power. [Solution] The hybrid work vehicle includes: an engine (1); a hydraulic pump (4) which is driven by the engine; a work device (5) which is disposed at the front of the vehicle and performs work using the hydraulic pump as a drive source; a motor/generator (6) which generates electric power by use of the torque of the engine; and a travel drive device which causes the vehicle to travel by rotating and driving wheels by use of the electric power generated by the motor/generator. The hybrid work vehicle is steered while the vehicle bends by way of a center joint (15). The travel drive device includes: a plurality of electric motors (21 and 22); and a propeller shaft (8) which is linked with the plurality of electric motors and transmits motive power from the plurality of electric motors to the wheels.

Abstract: There is provided an electrically driven working vehicle that needs reduced assisting power from an electrical storage device when accelerating subsequent to modulation and still obtains acceleration at least equivalent to that of torque converter vehicles. The electrically driven working vehicle has an engine 1, a generator motor 5 connected mechanically to the engine 1, a generator inverter 6 for controlling the amount of power generated by the generator motor 5, a traveling motor 7 for driving a vehicle body, an electrical storage device 3 connected electrically to the generator inverter 6 and to the traveling motor 7, and a forward/reverse switching device 103 for switching the traveling direction of the vehicle body.

Abstract: A construction vehicle control apparatus is provided including: a motor generator control unit (160) which, when regenerative electrical power generated by a motor (7) during regenerative braking surpasses acceptable charging electrical power of a capacitor (3), drives a motor generator (5) using the surplus electrical power; an engine controller (2) which detects the rotating speed of an engine (1); a motor control unit (180) which, if the rotating speed of the engine becomes larger than a second set value while the motor generator is being driven by the surplus electrical power, reduces regenerative torque generated by the motor; and a brake control unit (190) which, if the rotating speed of the engine becomes larger than the second set value while the motor generator is being driven by the surplus electrical power, increases regenerative torque generated by a hydraulic brake (30).