To make it possible to prevent a decrease in work speed due to a decrease in the speed of a given actuator when an operator unintentionally performs a fine operation of the control lever of the other actuator in a state in which the given actuator is driven by the hydraulic fluid delivered from a plurality of pumps, a controller (41) sets, as a composite dead zone line serving as a boundary of a composite dead zone, a composite dead zone line such that as an operation amount in one direction of a control lever (12L) or (13L) of a control lever device (12) or (13) is increased, the width of the composite dead zone corresponding to an operation amount in the other direction of the control lever is widened, and corrects the operation amount in the other direction such that the demanded flow rate of an actuator increases from zero, when the control lever is operated in the other direction in a state in which the operation amount in the one direction of the control lever remains within a range of the composite dead zone, and the operation amount in the other direction exceeds the composite dead zone line.

A hose assembly for a hydraulic system is shown. The hose assembly includes a first hose that fluidly couples a pump with a hydraulic actuator using a first port. The first hose includes a first electronic device that provides identification information for the first hose. The hose assembly further includes a second hose that fluidly couples the hydraulic actuator with a reservoir tank using a second port. The second hose includes a second electronic device that provides identification information for the second hose. The hose assembly further includes a controller that receives a first connection signal and a second connection signal. The controller is further configured to determine that the first hose has fluidly coupled using the first port based on the first connection signal and determine that the second hose has fluidly coupled using the second port based on the second connection signal.

An excavator includes a control valve configured to control hydraulic oil to be supplied to an actuator, based on pilot pressure; an electric operation device configured to output an operation signal; a gate lock device; a gate lock valve provided on a pilot line supplying the pilot pressure to the control valve, and configured to open or close according to a state of the gate lock device, so as to switch between a locked state and a released state; a proportional valve provided on the pilot line; and a control part configured to receive as input the operation signal, to control the proportional valve, wherein the control part determines, in a case where the gate lock valve is in the locked state by the gate lock device and an operation is performed on the electric operation device, the operation as an operational error.

In the case of an incorrect polarity of connectors in hydraulic networks, a switching device is provided, and formed with a connector part, a valve body, a switching part displaced axially in the valve body within limits, a base part and a top part. Wherein cooperating annular chambers for the conducting of a working fluid are formed in the region of an inner surface of the valve body and an outer surface of the switching part. Annular surfaces (A2, A3, A5, A7) are acted upon with pressurized fluid on the switching part towards the top part and annular surfaces (A1, A4, A6) of the switching part are acted upon towards the base part have a following size relations when there is a permanent fluidic connection of the annular chambers:

A2=A3>0.5×A1;

A4>A5+A7;

A3+A7>A4+A6;

A1=2A2−A4+A5−A6+A7

A method for operating a hydraulic consumer on an electrically actuated control valve includes providing the valve with an open valve position for establishing a connection between a valve inlet and a pilot line for influencing a pivot angle set on an axial piston pump and a system pressure which is present at the valve inlet and dependent on the pivot angle. Data regarding the current system pressure and the current pivot angle are detected and communicated to a control unit. The method includes determining an incorrect setting of the control valve if the control unit detects that a delivery volume flow of the axial piston pump is smaller than a value to be expected based on valve position, or the control unit detects that the system pressure present at the valve inlet is at a maximum without a delivery volume flow flowing in the direction of the hydraulic consumer.

To make it possible to prevent a decrease in work speed due to a decrease in the speed of a given actuator when an operator unintentionally performs a fine operation of the control lever of the other actuator in a state in which the given actuator is driven by the hydraulic fluid delivered from a plurality of pumps, a controller (41) sets, as a composite dead zone line serving as a boundary of a composite dead zone, a composite dead zone line such that as an operation amount in one direction of a control lever (12L) or (13L) of a control lever device (12) or (13) is increased, the width of the composite dead zone corresponding to an operation amount in the other direction of the control lever is widened, and corrects the operation amount in the other direction such that the demanded flow rate of an actuator increases from zero, when the control lever is operated in the other direction in a state in which the operation amount in the one direction of the control lever remains within a range of the composite dead zone, and the operation amount in the other direction exceeds the composite dead zone line.

A hose assembly for a hydraulic system is shown. The hose assembly includes a first hose that fluidly couples a pump with a hydraulic actuator using a first port. The first hose includes a first electronic device that provides identification information for the first hose. The hose assembly further includes a second hose that fluidly couples the hydraulic actuator with a reservoir tank using a second port. The second hose includes a second electronic device that provides identification information for the second hose. The hose assembly further includes a controller that receives a first connection signal and a second connection signal. The controller is further configured to determine that the first hose has fluidly coupled using the first port based on the first connection signal and determine that the second hose has fluidly coupled using the second port based on the second connection signal.

The present invention provides a low-cost detachment determining device capable of determining whether or not an electromagnetic valve-equipped device has been detached. The detachment determining device determines whether or not at least a part of an electromagnetic valve-equipped device included in an industrial machine, such as a construction machine or an industrial vehicle, has been detached from the industrial machine, the electromagnetic valve-equipped device being a hydraulic device equipped with an electromagnetic valve. The detachment determining device includes: an electrical characteristic detecting portion configured to output a detection signal to the electromagnetic valve-equipped device and detect an electrical characteristic of the electromagnetic valve-equipped device based on the detection signal; and a detachment determining portion configured to determine, based on a plurality of electrical characteristics detected at different time points by the electrical characteristic detecting portion, whether or not at least a part of the electromagnetic valve-equipped device has been detached.

A hydraulic tank protection system is disclosed. The hydraulic tank protection system may include a sensor to detect a characteristic of a fluid, a fluid control device to control a flow of the fluid into or out of a reservoir of a hydraulic tank, and an electronic control module to: receive, from the sensor, information indicating the characteristic of the fluid, determine, based on the characteristic of the fluid, whether the fluid comprises a first type of fluid, and selectively provide a control signal to actuate the fluid control device to control the flow of the fluid into or out of the reservoir based on whether the fluid comprises the first type of fluid.

The present invention relates to a hydraulic switch arrangement and a fluid switch for incorporating into a hydraulic switch arrangement that may be included in a hydraulic circuit for inhibiting flow of hydraulic fluid through a hydraulic circuit in the event of movement of an apparatus or platform from a stable to an unstable condition. Such platforms or apparatus may include for example, cranes, excavators, teletrucks and forklift trucks and roll over incidents of such machinery is common leading to numerous fatalities. Aspects of the present invention ensure fast switching in the event of a transfer from a stable to an unstable condition.