摘要:
An input/output port 1 of a hose rupture control valve unit 100 is attached to a bottom port of a hydraulic cylinder 102, and an input/output port 2 is connected to one of actuator ports of a control valve 103 via an actuator line 105. The valve unit comprises a poppet valve body 5 serving as a main valve, a first spool valve body 6 serving as a pilot valve operated with a pilot pressure supplied as an external signal and having a pilot variable throttle portion 6a to operate the poppet valve body 5, a second spool valve body 50 operated with a pilot pressure and having a sub-variable throttle portion 50a to control a sub-flow rate, and a small relief valve 7 having the function of an overload relief valve.
摘要:
A hydraulic drive system includes a hose rupture control valve unit 200 having a poppet valve member 5 serving as a main valve for opening and closing communication between a cylinder connection chamber 8 and a hose connection chamber 9, a spool valve member 6 disposed in pilot passages 15a, 15b connecting a back pressure chamber 10 and the hose connection chamber 9 of the poppet valve member 5. The spool valve member is operated by a pilot pressure supplied as an external signal and operates the poppet valve member 5, and a small relief valve 7 having the function of an overload relief valve. A check valve 39 is disposed in the pilot passage 15b for cutting off a flow of the hydraulic fluid from the hose connection chamber 9 to the back pressure chamber 10. A hose rupture control valve unit 200 comprises a poppet valve member 5 serving as a main valve for opening and closing communication between a cylinder connection chamber 8 and a hose connection chamber 9, a spool valve member 6 disposed in pilot passages 15a, 15b connecting a back pressure chamber 10 and the hose connection chamber 9 of the poppet valve member 5, the spool valve member being operated by a pilot pressure supplied as an external signal and operating the poppet valve member 5, and a small relief valve 7 having the function of an overload relief valve. The valve unit further comprises a check valve 39 disposed in the pilot passage 15b for cutting off a flow of the hydraulic fluid from the hose connection chamber 9 to the back pressure chamber 10.
摘要:
A hydraulic drive system is provided with a front casing 50 and a rear ceasing 51. The front casing 50 is formed of a single member, and accommodates therein rotary members, which include a cylinder block 30A and the like, and a part of an output shaft 36 of a hydraulic motor 30 and rotary members, which include a cylinder block 31A and the like, and a part of an output shaft 32 of a hydraulic motor 31. The rear casing 51 is joined to the front casing 50, and has a ports plate 30C and a ports plate 31C arranged therein. The rear casing 51 has an oilway 52 communicating to a first port 30C1 of the ports plate 30C, an oilway 53 communicating to the oilway 52 and also communicating to a first port 31C1 of the ports plate 31C, an oilway 54 communicating to a second port 30C2 of the ports plate 30C, and an oilway 55 communicating to the oilway 54 and also communicating to a second port 31C2 of the ports plate 31C.
摘要:
To permit using hold-side pressure oil in a first hydraulic cylinder for the acceleration of a second hydraulic cylinder upon performing a combined operation of the first and second hydraulic cylinders, a hydraulic drive system is provided with a main hydraulic pump 21, a boom cylinder 6 and an arm cylinder 7, a directional control valve 23 for a boom and a directional control valve 24 for an arm, and a boom control device 25 and an arm control device 26. The hydraulic drive system is also provided with a pressure oil feed means for feeding pressure oil in a rod chamber 6b of the boom cylinder 6 to an upstream side of the directional control valve 24 for the arm when a bottom pressure of the arm cylinder 7 has increased to a high pressure equal to or higher than a predetermined pressure. This pressure oil feed means includes a flow combiner valve 44 arranged in a reservoir line 42 which can communicate to the rod chamber 6b of the boom cylinder 6. When the bottom pressure of the arm cylinder 7 is the predetermined pressure or higher, the flow combiner valve 44 maintains a communication line 40, which communicates the reservoir line 42 and the upstream side of the directional control valve 24 for the arm with each other, in a state that pressure oil can be fed to the upstream side of the directional control valve 24 for the arm.
摘要:
To keep one of three hydraulic pumps unaffected by variations in torque of the remaining hydraulic pumps when the three hydraulic pumps are used, displacements of the first and second hydraulic pumps are controlled based on their own delivery pressures P1,P2 and a pressure P3′ obtained by reducing through a reducing valve 14 a delivery pressure P3 from the third hydraulic pump, while a displacement of the third hydraulic pump 3 is controlled only by its own delivery pressure P3. The pressure oil delivered from the third hydraulic pump 3, therefore, remains unaffected by variations in delivery flow rates from the first and second hydraulic pumps 1,2, in other words, by variations in their torque consumptions, so that the third hydraulic pump is assured to provide a stable flow rate.
摘要:
To permit using hold-side pressure oil in a first hydraulic cylinder for the acceleration of a second hydraulic cylinder upon performing a combined operation of the first and second hydraulic cylinders, a hydraulic drive system is provided with a main hydraulic pump 21, a boom cylinder 6 and an arm cylinder 7, a directional control valve 23 for a boom and a directional control valve 24 for an arm, and a boom control device 25 and an arm control device 26. The hydraulic drive system is also provided with a pressure oil feed means for feeding pressure oil in a rod chamber 6b of the boom cylinder 6 to an upstream side of the directional control valve 24 for the arm when a bottom pressure of the arm cylinder 7 has increased to a high pressure equal to or higher than a predetermined pressure. This pressure oil feed means includes a flow combiner valve 44 arranged in a reservoir line 42 which can communicate to the rod chamber 6b of the boom cylinder 6. When the bottom pressure of the arm cylinder 7 is the predetermined pressure or higher, the flow combiner valve 44 maintains a communication line 40, which communicates the reservoir line 42 and the upstream side of the directional control valve 24 for the arm with each other, in a state that pressure oil can be fed to the upstream side of the directional control valve 24 for the arm.
摘要:
To keep one of three hydraulic pumps unaffected by variations in torque of the remaining hydraulic pumps when the three hydraulic pumps are used, displacements of the first and second hydraulic pumps are controlled based on their own delivery pressures P1, P2 and a pressure P3′ obtained by reducing through a reducing valve 14 a delivery pressure P3 from the third hydraulic pump, while a displacement of the third hydraulic pump 3 is controlled only by its own delivery pressure P3. The pressure oil delivered from the third hydraulic pump 3, therefore, remains unaffected by variations in delivery flow rates from the first and second hydraulic pumps 1,2, in other words, by variations in their torque consumptions, so that the third hydraulic pump is assured to provide a stable flow rate.
摘要:
A method and system for managing a construction machine whereby working time for each of different parts of a hydraulic excavator is measured. Measured data is stored in a memory of a controller and then transferred to a base station computer via satellite communication to be stored in a database. At each repair/replacement of a part in each hydraulic excavator, the base station computer calculates, based on the operation data, a replacement time interval of the part on the basis of the working time per section to which the part belongs, and then stores and accumulates it. The base station computer also reads the stored data for each hydraulic excavator, determines, for each part, a replacement rate of the part having a substantially equal replacement time interval, and calculates a target replacement time interval of the part in accordance with the replacement time interval corresponding to a maximum replacement rate.
摘要:
A function changing system of construction machinery includes a hydraulic excavator and a base station. The hydraulic excavator is deployed at a construction site and is provided with a rewritable memory storing control programs and/or data required for control of the machinery, a CPU for reading out the control programs from the memory and executing them, and a communications device The base station is provided with a communications device, a center server for identifying the serial number of the hydraulic excavator and transferring information with the control unit, and a database managed by the center server and storing control programs corresponding to the hydraulic excavator. When changing or switching an attachment of the hydraulic excavator, information is transferred with the center server of the base station and the control programs or data stored in the storage unit are rewritten to enable work suited to the changed part.
摘要:
The position of a working machine is detected, a position signal representing the detected position is transmitted, the position signal is received, management information relating to the working machine is calculated based on the received position signal, and the calculated management information is transmitted to the working machine. Example of management information is type of attachment depending on soil quality, and weather forecasts.