Patent application number | Description | Published |
20100186402 | PUMP TORQUE CONTROL SYSTEM FOR HYDRAULIC CONSTRUCTION MACHINE - A pump torque control system is capable of preventing hunting due to interference between speed sensing control and control of an engine speed of a prime mover when the temperature of a hydraulic fluid is low. | 07-29-2010 |
20100332088 | Engine Control System for Construction Machine - To provide an engine control system for a construction machine, which can decrease a consumption of energy to be required for the reduction of an engine lag-down that occurs upon a sudden increase in load, such as upon quick manipulation of a control device, is provided with a load condition detecting unit, a charge amount detecting unit, a boost pressure sensor, and a determination processing unit. The load condition detecting unit includes a manipulation stroke detector for detecting that a control device has been fully manipulated, and also, a first computation unit of a controller. The charge amount detecting unit can detect an amount of charge in a capacitor. The determination processing unit includes a determination processing unit of the controller. The determination processing unit performs processing to feed electric power from the capacitor to an electric motor if, when it has been detected in concomitance with manipulation of the control device by the load condition detecting means that a torque to be absorbed by a pump would exceed an output torque of an engine, a boost pressure detected by the boost pressure sensor is determined to be lower than a predetermined pressure, and moreover, an amount of charge in the capacitor as detected by the charge amount detecting unit is determined to be an amount of charge that can drive the electric motor for a predetermined time. | 12-30-2010 |
20110192155 | Hydraulic Drive Device for Hydraulic Excavator - The operability when performing a combined arm-crowd and bucket operation can be improved. A hydraulic drive device for a hydraulic excavator includes: a bucket directional control valve and a second arm directional control valve, which are connected in parallel tandem with a first hydraulic pump; a first arm directional control valve that is connected to a second hydraulic pump; and a flow rate restriction device that restricts the flow rate of pressure oil supplied to the second arm directional control valve, during crowd operation of a bucket. This flow rate restriction device includes a variable throttle whose opening is controlled so as to become smaller as a bucket operating device is operated to the crowd side, the variable throttle being provided in a bypass path connecting to the supply port of the second arm directional control valve. | 08-11-2011 |
20110192156 | Hydraulic Drive Device for Construction Machine - 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 | 08-11-2011 |
20120000191 | Hydraulic Driving Device for Work Machine - 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 S | 01-05-2012 |
20120003069 | Hydraulic Drive Apparatus for Construction Equipment - A hydraulic drive system for a working machine provides improved safety during forced regeneration. Upon input of a forced regeneration command signal from a forced regeneration switch, a controller detects non-operated states of all hydraulic actuators such as an arm cylinder arranged on a hydraulic excavator based on a lock detection signal from a gate lock detection switch, and also an attitude of a front working mechanism. The attitude is proper from the standpoint of safety. The detection is based on an arm angle signal from an arm angle sensor, a bucket angle signal from a bucket angle sensor and a boom pressure signal from a boom pressure sensor. Taking the detection of the non-operated states and proper attitude as conditions, the controller outputs control signals to a boosting proportional solenoid valve and flow-rate controlling, proportional solenoid valve to make a forced regenerator conduct forced regeneration. | 01-05-2012 |
20120163949 | Hydraulic Drive Device for Hydraulic Working Machine - A hydraulic drive system realizes a jack-up operation without arrangement of a flow rate control valve and center bypass selector valve. The hydraulic drive system has first and second hydraulic pumps, first and second directional control valves for controlling boom cylinders, a third directional control valve for controlling the boom cylinders, and a third hydraulic pump for feeding pressure oil to the third directional control valve. A jack-up selector valve has a second select position where, when a pressure in bottom chambers of the boom cylinders is not higher than a predetermined pressure, feeding of pressure oil, which is delivered from the first hydraulic pump and second hydraulic pump, to rod chambers of the boom cylinders, is held permissible in association with switching of the second directional control valve and third directional control valve by a manipulation of a control device. | 06-28-2012 |
20120260637 | Hydraulic Driving Device for Working Machine - A hydraulic driving device for a working machine surely prevents behavior of a single rod double acting cylinder not intended by an operator when discharge pressure of a main pump is raised to raise exhaust gas temperature to temperature required for burning particulate matter. A selector valve | 10-18-2012 |
20120285157 | PUMP CONTROL UNIT FOR HYDRAULIC SYSTEM - During a swing start, a pump torque calculating section associated with pump delivery pressure, a pump torque calculating section associated with swing operation pressure, and a maximum value selecting section of a controller perform control to change a maximum absorption torque of a second hydraulic pump between Tb and Tc in accordance with a delivery pressure of the second hydraulic pump. In an operation combining swing with other motion, a subtraction section performs a calculation to subtract a maximum absorption torque Tp | 11-15-2012 |
20120291427 | ATTACHMENT CONTROL APPARATUS FOR HYDRAULIC EXCAVATOR - In an attachment control apparatus for a hydraulic excavator having a hydraulic circuit that includes a hydraulic pump, a plurality of actuators having a breaker which is an attachment actuator, and a plurality of flow control valves having an attachment flow control valve that is switched by operation pilot pressure from a control pedal device to supply delivery fluid of the hydraulic pump to the attachment actuator, if the control pedal device is operated in a state where an attachment mode is not selected by an attachment selection device, the movement of the attachment actuator is limited. Thus, failure and reduced life of the attachment and other hydraulic devices can be prevented in the event that an operator has forgotten to switch from a normal mode to an attachment mode and has operated the attachment. | 11-22-2012 |
20130263587 | Relief Pressure Control Device for Hydraulic Work Machine - A relief pressure control system is provided with a controller for outputting, responsive to an adjustment signal output from a dial switch, a control signal to control a relief pressure of a variable solenoid relief valve, a display unit for displaying, responsive to display signals outputted from the controller, a relationship between a circuit pressure output from a pressure sensor and a pressure required by a hydraulic cylinder, and a control device constituting a start instruction unit for instructing a start of control of the variable solenoid relief valve. Stop valves are arranged in sections of main lines, which communicate a directional control valve and the hydraulic cylinder with each other, to open or close the section. The sections are located between positions on the main lines, where the variable solenoid relief valves are connected to the main lines, respectively, and the hydraulic cylinder. | 10-10-2013 |
20140090369 | Hydraulic Drive Device for Working Machine - A hydraulic drive device for a hydraulic excavator, includes: a first hydraulic pump; a first boom directional control valve and a second arm directional control valve which are connected in parallel to the first pump; a second hydraulic pump; and a second boom directional control valve and a first arm directional control valve which are connected in parallel to the second pump; wherein: the hydraulic drive device also includes: a third hydraulic pump; a third boom directional control valve connected to the third pump and controlling the flow of pressure oil supplied to a boom cylinder; and a third arm directional control valve connected in tandem with the third boom directional control valve and controlling the flow of pressure oil supplied to an arm cylinder. | 04-03-2014 |