Abstract: An engine control device of a work machine controls an internal-combustion engine of the work machine including a swing body, an implement attached to the swing body, a hydraulic actuator that operates the implement, a hydraulic pump that operates the hydraulic actuator, and the internal-combustion engine that drives the hydraulic pump and of which a rotation speed is changed according to a load. The engine control device of the work machine includes: a determination unit configured to determine whether a condition not requiring work with the implement is established; and an engine control unit configured to enable control at relief time of determining a target rotation speed targeted by the internal-combustion engine based on horsepower sucked by the hydraulic pump of when a hydraulic oil ejected by the hydraulic pump is relieved when the condition is established, and disables the control at relief time when the condition is not established.

Abstract: The gross output power of an engine distributed to at least one main machine and one auxiliary machine. A total load value calculation unit calculates the value of the lost power consumed by the auxiliary machine, and calculates the value of total load power by adding to this lost power value a target value for the main output power of the engine to be distributed to the main machine. A gross output value control unit controls the value of the gross output power so that the value of the gross output power becomes equal to the value of the total load power when the value of the total load power is less than a predetermined threshold value, and so that the value of the gross output power becomes equal to the above described threshold value when the value of the total load power is greater than the threshold value.

Abstract: A control method for a hybrid work machine including an internal combustion engine which includes an exhaust gas treatment device, a generator motor which is connected to an output shaft of the internal combustion engine, and an electrical storage device which stores electric power generated by the generator motor or supplies electric power to the generator motor, the control method for the hybrid work machine includes: determining whether the hybrid work machine is in a regeneration state in which a regeneration is performed by the exhaust gas treatment device; setting a threshold value for starting a generation of power by the generator motor to a minimum generation torque as a lower limit value when it is determined that the exhaust gas treatment device performs a regeneration; and controlling the generator motor based on the set threshold value.

Abstract: An engine control device of a work machine controls an internal-combustion engine of the work machine including a swing body, an implement attached to the swing body, a hydraulic actuator that operates the implement, a hydraulic pump that operates the hydraulic actuator, and the internal-combustion engine that drives the hydraulic pump and of which a rotation speed is changed according to a load. The engine control device of the work machine includes: a determination unit configured to determine whether a condition not requiring work with the implement is established; and an engine control unit configured to enable control at relief time of determining a target rotation speed targeted by the internal-combustion engine based on horsepower sucked by the hydraulic pump of when a hydraulic oil ejected by the hydraulic pump is relieved when the condition is established, and disables the control at relief time when the condition is not established.

Abstract: A hybrid work machine engine control device which is mounted on a hybrid work machine having a working unit that operates with operating oil supplied from a hydraulic pump and which controls an internal combustion engine that drives a generator motor and the hydraulic pump with generated power, includes: a processing unit that increases torque required for the generator motor to generate electric power with a lapse of time and decreases absorption torque that the hydraulic pump absorbs when the generator motor generates electric power during operation of the internal combustion engine.

Abstract: A control method for a hybrid work machine that includes an internal combustion engine that drives a working unit, and a generator motor connected to the internal combustion engine and transfers and receives electric power to/from a power storage device, the control method includes: determining whether a situation is at a time of an output limitation in which an output of the internal combustion engine is limited; at the time of the output limitation, limiting an assist operation of supplying the electric power stored in the power storage device to the generator motor in a case of increasing an output of the internal combustion engine based on a work request for the working unit at a time of working; and controlling the internal combustion engine and the generator motor in a state in which the assist operation is limited.

Abstract: A construction machine includes a swing speed detection unit that detects an actual swing speed of an upper structure, a lever command speed calculation unit that calculates a lever command speed based on an operation amount of a swing lever for swinging the upper structure, a torque command value calculation unit that calculates a torque command value based on a command speed based on the calculated lever command speed, a command value output unit that outputs a command torque to a rotary motor generator based on the torque command value calculated by the torque command value calculation unit and the swing speed detected by the swing speed detection unit, and a command value output restriction unit that restricts the output of the torque command value from the command value output unit under predetermined conditions.

Abstract: In controlling an engine generating motive power of which an output shaft extracting the generated motive power is connected to a generator motor, an engine control device causes the generator motor to generate motive power when both of a first condition satisfied based on a comparison of an actual revolution speed of the engine with a revolution speed acquired from first and second relationships and a second condition satisfied based on a comparison of a torque of the engine at the actual revolution speed with a torque acquired using the first relationship at the actual revolution speed are satisfied. The first relationship is between the revolution speed of the engine and the torque generated by the engine at the revolution speed, and the second relationship is between the torque and the revolution speed of the engine and defines a magnitude of the motive power generated from the engine.

Abstract: A rotation control system of a hoist pump includes: the hoist pump (3); an engine (2) for driving the hoist pump (3); a working equipment driven by a hydraulic cylinder that is extendable by hydraulic oil delivered through the hoist pump (3); a hydraulic oil tank that stores the hydraulic oil supplied to the hoist pump (3) and receives the hydraulic oil returned from the hydraulic cylinder; and a controller (9) that controls a rotation speed of the hoist pump (3) to be an allowable rotation speed that is set in advance for preventing cavitation while the hydraulic cylinder is operated.

Abstract: The gross output power of an engine distributed to at least one main machine and one auxiliary machine. A total load value calculation unit calculates the value of the lost power consumed by the auxiliary machine, and calculates the value of total load power by adding to this lost power value a target value for the main output power of the engine to be distributed to the main machine. A gross output value control unit controls the value of the gross output power so that the value of the gross output power becomes equal to the value of the total load power when the value of the total load power is less than a predetermined threshold value, and so that the value of the gross output power becomes equal to the above described threshold value when the value of the total load power is greater than the threshold value.

Abstract: A rotation control system of a hoist pump includes: the hoist pump (3); an engine (2) for driving the hoist pump (3); a working equipment driven by a hydraulic cylinder that is extendable by hydraulic oil delivered through the hoist pump (3); a hydraulic oil tank that stores the hydraulic oil supplied to the hoist pump (3) and receives the hydraulic oil returned from the hydraulic cylinder; and a controller (9) that controls a rotation speed of the hoist pump (3) to be an allowable rotation speed that is set in advance for preventing cavitation while the hydraulic cylinder is operated.

Abstract: A gear change control device and a method for a work vehicle for reducing a heat quantity generated by gear shift clutches of a transmission and a gear shift shock to reduce a load on the clutches without inducing elongation of a cycle time or deterioration of a work efficiency. A clutch pressure (Pm) of an input clutch(10) is reduced to switch from a connected state to a power-transmittable sliding state at a time (tE) after a time (tA) at which a cut-off operation of a gear shift clutch used before gear shifting (reverse clutch 22) is started and before a time (tD) at which the connecting operation of a selected gear shift clutch to be used after the gear shifting (forward clutch 21) is completed.

Abstract: A controller serving as determination device determines whether or not a rising speed of the clutch pressure of the input clutch is less than a limit rising speed of the original pressure. A controller serving as original pressure control device adjusts the original pressure such that a difference between the original pressure and the detected clutch pressure of the input clutch becomes a predetermined offset pressure when it is determined that the clutch pressure rising speed of the input clutch is less than the original pressure limit rising speed, and adjusts the original pressure such that the original pressure is raised at the original pressure limit rising speed when it is determined that the clutch pressure rising speed of the input clutch is equal to or higher than the original pressure limit rising speed.

Abstract: A gear change control device and a method for a work vehicle for reducing a heat quantity generated by gear shift clutches of a transmission and a gear shift shock to reduce a load on the clutches without inducing elongation of a cycle time or deterioration of a work efficiency. A clutch pressure (Pm) of an input clutch(10) is reduced to switch from a connected state to a power-transmittable sliding state at a time (tE) after a time (tA) at which a cut-off operation of a gear shift clutch used before gear shifting (reverse clutch 22) is started and before a time (tD) at which the connecting operation of a selected gear shift clutch to be used after the gear shifting (forward clutch 21) is completed.

Abstract: Large torque variation is suppressed by preventing the rapid connection (engagement) of an input clutch when a brake is released. When fine adjustment is performed with the use of brake operating means such as a brake pedal, a clutch pressure of the input clutch is varied with high responsiveness to the change of the brake operating means to enable the fine adjustment with high accuracy. Clutch pressure detection means detects a clutch pressure of the input clutch. A controller serving as determination means determines whether or not a rising speed of the clutch pressure of the input clutch is less than a limit rising speed of the original pressure.