摘要:
A material handling machine includes an arm moveable relative to a chassis of the machine, a first hydraulic actuator operable to lift and lower the arm relative to the chassis, a ground engaging implement mounted on the arm and moveable relative to the arm, a second hydraulic actuator operable to move the ground engaging implement relative to the arm, the second hydraulic actuator having a pressured chamber, pressure within the pressure chamber being indicative of a force of engagement between the ground engaging implement and the ground, and a control system. The control system defines a target pressure for the pressure chamber, the control system being arranged such that when a pressure within the pressured chamber exceeds the target pressure the control system operates the first hydraulic actuator to lift the arm to reduce the force of engagement between the ground engaging implement and the ground.
摘要:
[Problem] To provide a hydraulic drive system for a hydraulic excavator, which makes it possible to efficiently perform grading work by using residual energy of pressure oil in a hydraulic circuit although no attention has been paid to the residual energy in conventional technologies.[Solution] A hydraulic drive system for a hydraulic excavator is provided with a boom cylinder 1 and arm cylinder 2, a main hydraulic pump 4 for feeding pressure oil to both the cylinders 1,2, a directional control valve 7 for a boom and directional control valve 8 for an arm to control flows of pressure oil to be fed to the boom cylinder 1 and arm cylinder 2, respectively, and a reservoir line 8c connecting the directional control valve 8 for the arm with a working oil reservoir 6. A flow-rate control valve 15 capable of selectively closing the reservoir line 8c is arranged and, when a rod-side hydraulic pressure of the arm cylinder 2 has increased to a preset value or greater while grading work is performed by a combined operation of boom raising and arm crowding, the reservoir line 8c is closed by the flow-rate control valve 15 to prevent drainage of rod-side pressure oil from the arm cylinder 2 to the working oil reservoir 8c and to feed the rod-side pressure oil to a bottom side of the boom cylinder 1.
摘要翻译:[问题]提供一种液压挖掘机的液压驱动系统,其能够通过使用液压回路中的压力油的剩余能量来有效地进行分级工作,尽管在传统技术中没有注意剩余能量。 [解决方案]液压挖掘机的液压驱动系统设置有动臂缸1和斗杆缸2,用于向两个缸1,2供应压力油的主液压泵4,用于吊杆的定向控制阀7和定向 用于臂的控制阀8分别控制供给到动臂缸1和斗杆缸2的压力油的流动;以及将臂的方向控制阀8与工作油储存器6连接的储存管路8c。 布置有能够选择性地关闭储存管路8c的流量控制阀15,并且当臂缸2的杆侧液压压力增加到预设值以上时,通过起重臂升高和 手臂挤压时,储液管路8c被流量控制阀15封闭,以防止杆侧压力油从臂缸2向工作油储存器8c排出,并将杆侧压力油供给到底侧 o 臂臂1。
摘要:
A fluid system includes first and second control valves that control fluid communication with first and second actuators. The first control valve may combine fluid flow from a second end port of the first actuator with fluid flow from a pressurized fluid source when providing a supply of fluid to a first end port of the first actuator. The first and second control valves include first and second signal ports in fluid communication with the supply of fluid to the first and second actuators. A resolver outputs a resolved signal pressure equal to the greater of a first signal pressure output by the first signal port and a second signal pressure output by the second signal port. A compensator in fluid communication with the first control valve and the first actuator controls fluid flow from the first control valve to the first actuator based on the resolved signal pressure.
摘要:
A hydraulic regeneration system for a work machine is provided. The hydraulic regeneration system includes a first hydraulic actuator having a first chamber and a second chamber, a second hydraulic actuator having a third chamber and a fourth chamber, and a source of pressurized fluid. A first directional control valve is disposed between the source of pressurized fluid and the first chamber of the first hydraulic actuator and the third chamber of the second hydraulic actuator. A second directional control valve is disposed between the source of pressurized fluid and the second chamber of the first hydraulic actuator and the fourth chamber of the second hydraulic actuator. An accumulator may also be used to store pressurized fluid and selectively supply pressurized fluid to increase the efficiency of the work machine.
摘要:
These and other features and objects are achieved by providing an over-running load control valve integral with the remote valve section of an agricultural tractor to allow it to efficiently work in a multipurpose agricultural environment. A counterbalance cartridge valve, with reverse flow check, is manifolded to an agricultural remote valve section.
摘要:
A hydraulic damper for a high speed actuator is provided to bring the actuator to rest with minimum oscillation around a target position. The hydraulic damper comprises a hydraulic circuit to communicate with the actuator over its entire positional range for the purpose of dampening a sudden stop of the actuator about a target position. The actuator is connected by a cable to a reel, the reel being connected to a shaft movement of the actuator produces rotation of the shaft. The shaft is also connected to a hydraulic motor which pumps hydraulic fluid through a hydraulic damper too, in effect, dampen the movement of the actuator.
摘要:
In a selective control device for plural kinds of oil-hydraulic actuators comprising an actuator selective valve for selecting an operative oil-hydraulic actuator from among plural kinds of oil-hydraulic actuators and a directional control valve for operating the selected actuator extendedly and retractedly, the actuator selective valve is provided with a quick extensional position which functions to connect an extensional pressure port thereof to a bottom side oil chamber of the selected actuator and also to connect a head side oil chamber to the bottom side oil chamber in order to extend the selected actuator quickly. The construction of the actuator selective valve eliminates a quick extensional valve adopted in a prior oil-hydraulic control device.
摘要:
In a directional control valve device, a first passage connects a second port with a first port by using a part of a movement path of a moving valve element when the moving valve element is in a position of a first end. A second passage connects the second port with the third port by using an internal passage of the moving valve element when the moving valve element is in a second end. The moving valve element is provided with a first check valve for permitting a flow in the internal passage only in the direction from the third port to the second port. When a fluid pressure is applied to the third port, the fluid pressure presses the moving valve element toward the second end so that the first passage is closed, and the first check valve is opened to open the second passage.
摘要:
A hydraulic valve assembly includes a pressure compensating valve in which a compensator spool is slideably received in a bore. A pre-compensator gallery connected to a metering orifice, a preload gallery leading to a hydraulic actuator, an auxiliary pump supply passage, and a load sense passage all open into the bore. The compensator spool moves in response to a pressure differential between the pre-compensator gallery and the load sense passage. That movement selectively opens and closes a first path between the pre-compensator gallery and the a preload gallery, and a second path between the auxiliary supply passage and the load sense passage. Control of these paths maintains a constant pressure drop across the metering orifice and generates a pressure signal that is employed to regulate pressure at an outlet of a pump.
摘要:
A control system for a hydraulic servomotor (13) is disclosed. The control system comprises an electro hydraulic actuator (2) comprising a number of valves (9, 10, 11, 12, 18) for controlling fluid flows, a main control module (1), and one or more connectors. The control system further comprises at least one extension control module (3) comprising one or more connectors. Finally, the control system comprises means (6) for communicating signals between the main control module (1) and each of the extension control module(s) (3).Since the main control module (1) and the extension control module(s) (3) are able to communicate signals, it is possible to provide signals to/from the main control module (1) via an extension module (3), thereby in effect providing additional connectors to the main control module (1). Thereby the main control module (1) may be able to perform additional functions as compared to similar prior art control modules.