摘要:
A hydraulic control arrangement includes a common variable displacement pump configured to supply pressure medium to two consumer groups. The pressure level of a control block assigned to one of the consumer groups is set to a different pressure level than that of a further control block assigned to the other consumer group.
摘要:
A hydraulic control assembly, in particular for controlling hydraulic consumers of a mobile machine, includes a load reporting line (26) that can be subjected to the highest load pressure of a plurality of hydraulic consumers, triggered simultaneously each via a respective main control valve (38, 57), and that is connectable by an end portion (26a) to a pump regulator (25). A pressure limiting valve (50) limits the control pressure in the end portion (26a) of the load reporting line (26). The pressure limiting valve (50) is adjustable as a function of the magnitude of a pilot control signal serving to trigger a main control valve (38, 57).
摘要:
The invention relates to a hydraulic control system for providing at least one hydraulic consumer with a pressure medium. Said system comprises an LS pump system and a metering port for adjusting the pressure medium volume flow rate towards the consumer. The LS line is connected to a pressure medium sink via a current regulator. The invention is characterized in that the current regulator can be adjusted depending on the pump rate in order to modify the pressure drop at the metering port.
摘要:
The invention relates to a hydraulic control arrangement and to a method for controlling a hydraulic consumer that comprises a pressure chamber on the input side and on the return side, said pressure chamber being connected to an adjusting pump or a tank via a valve device. The valve device is controlled by means of a control unit via which it can be adjusted in a regeneration mode, in which both pressure chambers are connected to the adjusting pump. According to the invention, the adjusting pump is pressure controlled, whereby in the regeneration mode, it is automatically switched to the normal operation in which the supply side of the pressure chamber is connected to the adjusting pump and the return side of the pressure chamber is connected to the tank when the pumping rate falls below the demand for the pressure medium.
摘要:
What is disclosed is a control arrangement for an equipment, in particular a wheel loader or a backhoe loader having a shovel mounted articulatedly at a boom, wherein the control arrangement enables a control of the shovel by means of a control pressure of a boom control unit, so that the latter may be taken into a target position during lowering of the boom or while the boom is taken into a floating condition.
摘要:
On a work appliance, an extension arm is held rotatably, and a scoop is held rotatably on the extension arm. The actuation of the extension arm and of the scoop takes place in each case by means of a hydraulic cylinder. Each cylinder is assigned a valve which controls the flow of pressure medium from a pump to the cylinder and from the latter to the tank. A rotational movement of the extension arm entails a change in the angular position of the top edge of the scoop, this change having an adverse effect during the raising of the extension arm, particularly when the scoop is full. So that the top edge of the scoop maintains its angular position when the extension arm is being raised or lowered, the valves which control the flow of pressure medium to the cylinders can be activated in such a way that the ratio of the pressure medium quantities supplied to the cylinders is kept at a constant value independently of the size of the control signal controlling the flow of pressure medium to the cylinder for the actuation of the extension arm. The invention can be used advantageously in wheeled loaders, particularly in those wheeled loaders which are of simple construction.
摘要:
A hydraulic control arrangement is disclosed for the load pressure independent control of a consumer, comprising a distribution valve forming an inlet metering orifice, a corresponding individual pressure compensator, a stop valve provided for each consumer connection which may be released by means of a pilot valve and an anti-cavitation valve by means of which pressure medium can be drawn from a reservoir to avoid cavitation. According to the invention, the distribution valve and the stop valves are arranged along two parallel axes, while the axes of the two pilot valves are arranged perpendicularly to these two axes. The anti-cavitation valves in turn extend perpendicularly to the axes of the distribution valves, the stop valves and the anti-cavitation valves.
摘要:
A hydraulic control arrangement is disclosed for the load pressure independent control of a consumer, comprising a distribution valve forming an inlet metering orifice, a corresponding individual pressure compensator, a stop valve provided for each consumer connection which may be released by means of a pilot valve and an anti-cavitation valve by means of which pressure medium can be drawn from a reservoir to avoid cavitation. According to the invention, the distribution valve and the stop valves are arranged along two parallel axes, while the axes of the two pilot valves are arranged perpendicularly to these two axes. The anti-cavitation valves in turn extend perpendicularly to the axes of the distribution valves, the stop valves and the anti-cavitation valves.
摘要:
A hydraulic control arrangement which is provided for the demand-feed-regulated supply of pressure medium to preferably a plurality of hydraulic consumers by proportionally adjustable directional valves. There are hydraulic pumps by which pressure medium can be conveyed in a quantity corresponding to the demand into a common inflow line leading to the directional valves. A first demand-feed regulator is assigned to the first hydraulic pump and a second demand-feed regulator to the second hydraulic pump. The two demand-feed regulators are capable of being acted upon, with the effect of increasing the pressure medium quantity discharged into the inflow line by the corresponding hydraulic pump, by a spring and, on a first active surface, by the pressure in a load-signaling line and, with the effect of reducing the pressure medium quantity discharged into the inflow line by the corresponding hydraulic pump, on a second active surface, by a pump pressure. Moreover, a nonreturn valve opening toward the inflow line is arranged between the first hydraulic pump and said inflow line. Either both hydraulic pumps or only the second hydraulic pump conveys pressure medium to the inflow line. In order to be more flexible here, a nonreturn valve opening toward the inflow line is also arranged between the second hydraulic pump and the latter. There are also members by which action of force on the demand-feed regulators can be changed that the hydraulic consumers can be supplied with pressure medium both solely by the first hydraulic pump and solely by the second hydraulic pump.
摘要:
A method and apparatus for adjusting the working depth of a soil-moving (soil-working, tilling) machine carried by a tractor includes adjusting the position of the machine in relation to the tractor in dependence upon a traction signal and upon a position signal. The traction signal corresponds to the traction produced on the machine in the soil and the position signal corresponds to the position of the machine in relation to the tractor. A portion of the traction signal above a certain cut-off frequency and a portion of the position signal below the same cut-off frequency or below a lower one are utilized in the adjusting control.