Patent classifications
F15B2211/755
Control method for executing a floating function of a boom, corresponding control systems and work vehicles comprising such control systems
A control method for executing a floating function of a boom in a work vehicle includes determining that a predetermined floating function activation command has been inputted by the operator by means of a command input means. When the floating function activation command has been inputted by the operator, acquiring, a signal or data indicative of the current position of the boom along a travel path of the boom over time, the travel path including a first section between a boom full extension position and a deceleration position, a second section between the deceleration position and a grounding position, and a third section between the grounding position and a full retract position, and moving the boom from the current position, determined based on the signal or data indicative of the position of the boom, to the full retract position.
PARTIAL STROKE TESTS FOR SHUTDOWN VALVES
To generate a setpoint signal to stroke a valve during a partial-stroke test, a first target is determined for the setpoint signal based at least on a travel displacement threshold, the travel displacement threshold corresponding to a desired extent of travel of the valve during the partial-stroke test; the setpoint signal is ramped from an initial value to the first target, during a first time interval; subsequently to the first time interval, the setpoint signal is maintained at the first target during a second time interval; a second target is determined for the setpoint signal based at least on the initial value; and during a third time interval subsequent to the second interval, the setpoint signal is ramped from the first target to the second target in a direction opposite to the ramping of the setpoint signal during the first time interval.
CLOSED CENTER HOIST VALVE WITH SNUBBING
A valve for controlling a hydraulic cylinder on a work machine may include a raising position configured for placing a pump in fluid communication with a cap end of the hydraulic cylinder. The valve may also include closed center position configured for closing off fluid communication to the cap end line and the rod end line. The valve may also include a lowering position configured for placing the pump in fluid communication with the rod end of the hydraulic cylinder. The valve may also include a snubbing position configured for placing the cap end in restricted flow fluid communication with the tank and for placing the rod end in restricted flow fluid communication with the tank.
Slit valve pneumatic control
Disclosed are a slit valve apparatus and a method for controlling a slit valve. The slit valve apparatus includes a slit valve assembly and a servo-control system in communication with the slit valve assembly. The slit valve assembly includes at least one gate able to transition between an open position and a closed position, at least one pneumatic actuator, at least one proportional pneumatic valve including a plurality of controllers, and a continuous position sensor. The servo-control system includes a centralized controller that generates a control signal and adjusts the movement of the at least one gate based on the position trajectory for the gate, a linear position measurement of the gate from the continuous position sensor, and fluid pressure/flow measurements from the plurality of controllers.
FLUID ACTUATOR, FLUID ACTUATOR CONTROL METHOD, AND COMPUTER READABLE MEDIUM STORING CONTROL PROGRAM OF FLUID ACTUATOR
Provided is a fluid actuator capable of safely driving a drive target. An air actuator using air as a working fluid includes an X-axis pressure sensor that measures air pressures PX+ and PX− along one drive axis, which drives a drive target in an X direction, a Y-axis pressure sensor that measures air pressures PY1+, PY1−, PY2+, and PY2− along two drive axes, which drive the drive target in a Y direction, and an acceleration detection unit that detects translational acceleration and rotational acceleration generated in the drive target on the basis of the measured air pressures PX+, PX−, PY1+, PY1−, PY2+, and PY2−.
System and method for end position damping
A system including a pneumatic actuator with an actuator member and a compressed air supply device which is configured to apply compressed air to the pneumatic actuator in order to set the actuator member in an actuator member movement towards an end position of the pneumatic actuator, wherein the compressed air supply device is further configured to provide an end position damping for the actuator member movement and, during the end position damping, to adjust a conductance value of a discharge valve, via which the compressed air supply device discharges compressed air from a pressure chamber of the pneumatic actuator which pressure chamber counteracts the actuator member movement, in accordance with a conductance characteristic in dependence of a driving force acting on the actuator member.
Gas cylinder
A gas cylinder includes supply passages for supplying, to an accommodation chamber, a part of gas supplied to a second port. When the pressure in a first pressure chamber is equal to or lower than a prescribed pressure, a valve element closes a discharge flow passage by the biasing force of a spring member and the pressure in the accommodation chamber. When the pressure in the first pressure chamber exceeds the prescribed pressure, the valve element is moved by the pressure in the first pressure chamber, against the biasing force and the pressure in the accommodation chamber, to thereby open the discharge flow passage.
Partial stroke tests for shutdown valves
To generate a setpoint signal to stroke a valve during a partial-stroke test, a first target is determined for the setpoint signal based at least on a travel displacement threshold, the travel displacement threshold corresponding to a desired extent of travel of the valve during the partial-stroke test; the setpoint signal is ramped from an initial value to the first target, during a first time interval; subsequently to the first time interval, the setpoint signal is maintained at the first target during a second time interval; a second target is determined for the setpoint signal based at least on the initial value; and during a third time interval subsequent to the second interval, the setpoint signal is ramped from the first target to the second target in a direction opposite to the ramping of the setpoint signal during the first time interval.
HYDRAULIC CIRCUIT FOR A SWING SYSTEM IN A MACHINE
A hydraulic circuit is disclosed. The hydraulic circuit may include a hydrostatic pump to provide, at a flow rate, a fluid to a hydraulic motor, wherein the hydrostatic pump has a displacement, and wherein the hydraulic motor drives a swinging element; a swing circuit pressure sensor to sense a circuit pressure of the hydraulic circuit; a pilot pressure actuator to control, based on a supply pressure, the displacement of the hydrostatic pump; a pilot pressure override valve to control the supply pressure; and a controller configured to adjust, based on sensed signals and with the pilot pressure override valve, the supply pressure, wherein the sensed signals include: a circuit pressure signal based on the circuit pressure sensed by the swing circuit pressure sensor; and a sensed swing speed signal based on a swing speed of the swinging element sensed by one or more machine sensors.
HYDRAULIC DAMPENING SYSTEM FOR A REAR GATE OF A ROUND BALER
A hydraulic system for operating a rear gate of a baler implement includes a hydraulic cylinder having a housing that defines an interior, and a piston that is moveably disposed within the interior of the housing. The housing includes a first fluid port and a second fluid port, each disposed in fluid communication with a first fluid volume of the hydraulic cylinder. A flow rate control valve is moveable between a first position for directing fluid to or from the first fluid port at a first flow rate, and a second position for directing fluid to or from the second fluid port at a second flow rate. The second flow rate is different than the first flow rate.