Abstract: A hydraulic steering unit 5 generates a control pressure corresponding to the rotational quantity and rotational direction of the steering wheel 109 on the basis of pressurized oil of a pilot pump 13. Signals of pressure sensors 6a and 6b used to detect the control pressure, and a signal of a front operation detection unit 31, are inputted into a controller 132. A controller 32 and solenoid valves 33a and 33b control a stroke of a steering valve 4 so that the stroke becomes larger with increase in control pressure detected by each of the pressure sensors 6a and 6b. In addition, when the operation of a front work device is detected, the controller 32 and the solenoid valves 33a and 33b control the stroke of the steering valve 4 so that the stroke becomes larger than that provided when the operation of the front work device is not detected.

Abstract: Disclosed is a hydraulic drive system for a working machine, which enables to conduct forced regeneration continuously for a sufficient time. Based on an input of a lock detection signal S1 from a gate lock detection switch 40, a controller 50 detects that a gate lock lever 32 for controlling a gate lock on/off valve 33 is in a locked state, in other words, hydraulic actuators such as an arm cylinder 12 arranged on a hydraulic excavator 1 are all in non-operated states. Upon an input of a forced regeneration command signal So from a forced regeneration switch 53 in this detected state, control signals Cp,Cf are outputted to a boosting control valve 51 and regulator 52 to make a forced regeneration means (an arm cylinder control valve 27 and the regulator 52) conduct forced regeneration.

Abstract: An engine control device for work vehicle includes: a rotation speed control device that controls a rotation speed of an engine according to an operation amount of an accelerator pedal; a travel drive device that transmits a rotation of the engine to wheels through a torque converter and a transmission; a water temperature detection device that detects a physical quantity correlated with a cooling water temperature of the engine; a speed ratio detection device that detects a speed ratio of an input shaft and an output shaft of the torque converter; and a speed limit device that limits a maximum rotation speed of the engine to a limit rotation speed which is lower than an upper limit value if the water temperature detection device detects an overheat state in which the cooling water temperature is equal to or higher than a predetermined value when the speed ratio detected by the speed ratio detection device is in a limit speed ratio region where a torque converter efficiency is equal to or less than a predeter

Abstract: A prime mover revolution speed control system for a hydraulic construction machine sets the revolution speed of the prime mover in accordance with the operating state invoked by an operating command and as a result of a determination of an excavation state so that that the revolution speed of the engine can be increased for a heavy load (speedup) in the excavation state. When the control lever is fully operated in the direction of arm crowding, the control lever 43 is also operated, and first judgment conditions are all met to conclude that an excavation state has begun. During excavation work, when the control lever 44 is subjected to a half or greater operation in the arm crowding direction, second judgment conditions are all met to conclude that the excavation state persists, and the speedup sequence is continued.

Abstract: A hydraulic drive device for a construction machine which can reliably judge whether or not the state of the construction machine is appropriate for stopping an engine is provided. The hydraulic drive device includes: a main pump 13; a regulator 15 that controls the discharge rate of the main pump 13 by a control pressure Pc; an engine 16 that drives the main pump 13; an engine stopping unit 83 that stops the engine 16 when a predetermined state of the construction machine has continued for a predetermined period of time; and a pressure sensor 72 that detects the control pressure Pc. The engine stopping unit 83 has a control signal judging unit 81 that judges whether or not the control pressure Pc detected by the pressure sensor 72 is lower than a predetermined pressure value Pc1, as a judgment of whether or not the predetermined state of the construction machine is present.

Abstract: To provide a steering system for a construction vehicle, which is suited not only for traveling on general roadways but also for work at construction sites and can perform high-reliability steering control. A steering system for a construction vehicle is provided with a directional control valve 5 for controlling a flow of pressure oil to body-articulating hydraulic cylinders 2 that perform steering and also with a steering-wheel-operated signal generation means 6 for outputting by operation of a steering wheel 7a a pilot signal to the directional control valve 5 for switching the valve 5.

Abstract: A priority valve 7 is disposed between a hydraulic pump 2 and a steering valve 4 and is used to supply priority steering cylinders 103a and 103b with pressurized oil discharged from the hydraulic pump 2 by controlling the differential pressure across a meter-in hydraulic line of the steering valve 4 such that the differential pressure is kept at a target value. A pressure sensor 31 for detecting the load pressures of the steering cylinders 103a and 103b is provided. On the basis of the detected load pressures, the target value set for the priority valve 7 is modified by devices including a controller 32, a solenoid valve 33, a pilot hydraulic line 29, and a pressure receiving unit 24c of the priority valve 7. The above configuration enables suppression of a shock occurring at the start of turning of the steering wheel.

Abstract: A hydraulic steering unit 5 generates a control pressure corresponding to the rotational quantity and rotational direction of the steering wheel 109 on the basis of pressurized oil of a pilot pump 13. Signals of pressure sensors 6a and 6b used to detect the control pressure, and a signal of a front operation detection unit 31, are inputted into a controller 132. A controller 32 and solenoid valves 33a and 33b control a stroke of a steering valve 4 so that the stroke becomes larger with increase in control pressure detected by each of the pressure sensors 6a and 6b. In addition when the operation of a front work device is detected, the controller 32 and the solenoid valves 33a and 33b control the stroke of the steering valve 4 so that the stroke becomes larger than that provided when the operation of the front work device is not detected.

Abstract: A first hydraulic circuit leads, as clutch control pressure, pressurized oil supplied from a first hydraulic pump, to a transmission control device after regulating the pressurized oil, and leads, as torque converter operation oil, pressured oil to a torque converter, and leads pressurized oil to an oil cooler. Through a second hydraulic circuit, pressurized oil from a second hydraulic pump is distributed to a circuit portion downstream of the pressure regulation valve and upstream of a safety valve and to a circuit portion downstream of the torque converter and upstream of the oil cooler. A flow control device changes a proportion of a rate of flow in the second hydraulic circuit so that a proportion of the rate of flow to the circuit portion downstream of the torque converter and upstream of the oil cooler increases as pressure at an entrance of the torque converter increases.

Abstract: [Problem] To provide a steering system for a construction vehicle, which is suited not only for traveling on general roadways but also for work at construction sites and can perform high-reliability steering control. [Solution] A steering system for a construction vehicle is provided with a directional control valve 5 for controlling a flow of pressure oil to body-articulating hydraulic cylinders 2 that perform steering and also with a steering-wheel-operated signal generation means 6 for outputting by operation of a steering wheel 7a a pilot signal to the directional control valve 5 for switching the valve 5.

Abstract: Provided are a task processing system and a task processing method that can reduce power consumption and prevent overhead or processing load from increasing even with a system which performs frequency switching frequently. A main processor determines at least one of tasks to be executed by a sub processor in each of a plurality of time segment each having a predetermined length and determines, by the end of an nth (n is an integer that satisfies n?1) time segment, a clock frequency necessary for executing the task within an (n+1)th time segment based on information of a required number of cycles for the task to be executed by the sub processor in the (n+1)th time segment. The clock generation/control circuit supplies, in the (n+1)th time segment, to the sub processor a clock signal according to the clock frequency determined by the main processor in the nth time segment.

Abstract: An external module and a mobile communication terminal that facilitate collection of the internal state of a mobile communication terminal are provided. The external module is installed in the mobile communication terminal when the mobile communication terminal is in use and comprises: an internal information collection unit that communicates with the mobile communication terminal for collecting information relating to the internal states of the mobile communication terminal; and a memory for storing information that has been collected by the internal information collection unit. The mobile communication terminal has an internal state information acquisition unit for acquiring internal state information of the mobile communication terminal and supplying this internal state information to the external module.

Abstract: A priority valve 7 is disposed between a hydraulic pump 2 and a steering valve 4 and is used to supply priority steering cylinders 103a and 103b with pressurized oil discharged from the hydraulic pump 2 by controlling the differential pressure across a meter-in hydraulic line of the steering valve 4 such that the differential pressure is kept at a target value. A pressure sensor 31 for detecting the load pressures of the steering cylinders 103a and 103b is provided. On the basis of the detected load pressures, the target value set for the priority valve 7 is modified by devices including a controller 32, a solenoid valve 33, a pilot hydraulic line 29, and a pressure receiving unit 24c of the priority valve 7. The above configuration enables suppression of a shock occurring at the start of turning of the steering wheel.

Abstract: An external module and a mobile communication terminal that facilitate collection of the internal state of a mobile communication terminal are provided. The external module is installed in the mobile communication terminal when the mobile communication terminal is in use and comprises: an internal information collection unit that communicates with the mobile communication terminal for collecting information relating to the internal states of the mobile communication terminal; and a memory for storing information that has been collected by the internal information collection unit. The mobile communication terminal has an internal state information acquisition unit for acquiring internal state information of the mobile communication terminal and supplying this internal state information to the external module.

Abstract: An atomizing method for producing metal powder, including splitting molten metal in the vicinity of an exit of a nozzle by introducing the molten metal into a center of the nozzle, wherein gas is flowing through the nozzle. The split molten metal is then further split into fine particles by liquid ejected in an inverse cone shaped flow from a slit surrounding a lower side of the nozzle. The resulting powder is of fine size and spherical or granular shape, and is suitable for metal injection shaping.