A lift arm assembly for a power machine can include a lift arm, an implement carrier, a lift cylinder that raises or lowers the lift arm, a leveling link, a tilt cylinder that causes the implement carrier to pivot relative to the lift arm, and an isolated hydraulic circuit. The isolated hydraulic circuit can include a follower cylinder that is mechanically synchronized with the lift cylinder, a leveling cylinder that can be pivotally secured to the leveling link and to the lift arm, a first conduit that can provide hydraulic flow between base ends of the follower and leveling cylinders, and a second conduit that can provide hydraulic flow between rod ends of the follower and leveling cylinders. Movement of the follower and leveling cylinders can be hydraulically synchronized by flow through the first and second conduits.

A control method of a work machine includes: calculating a maximum flow rate of hydraulic oil discharged from a hydraulic pump; calculating a first target speed of working equipment including a bucket based on an operation amount of an operation device operated for driving a plurality of hydraulic actuators to which the hydraulic oil discharged from the hydraulic pump is supplied to drive the working equipment and a distance between the bucket and a target excavation landform; calculating a second target speed of the working equipment based on the maximum flow rate, and the operation amount of the operation device and the distance between the bucket and the target excavation landform; and outputting a control signal for controlling the hydraulic actuators based on a smaller one of the first target speed and the second target speed.

A work vehicle includes a work implement operatively connected to a frame through an actuator having a cylinder and a piston rod. Control circuitry is operatively connected to the actuator and includes a processer and a memory, wherein the memory is configured to store program instructions and the processor is configured to execute the stored program instructions to: identify one of an initial retracted reference position of the piston rod based on an initial minimum retracted distance or an initial extended reference position of the piston rod based on an initial maximum extended distance; identifying an end of stroke position of the piston rod after identifying one of the initial retracted reference position of the piston rod or the initial extended reference position of the piston rod; and moving the work implement with respect to the work vehicle based on a work implement command modified by the identified end of stroke position.

A protection system for a hydraulic cylinder piston having a barrel and a piston rod reciprocating therein, the protection system comprising a piston rod shield which is fixed with respect to the piston rod in use to move with respect to the barrel to cover the piston rod when the piston rod is exposed from the barrel and wherein the piston rod shield comprises a non-metallic flexible material which substantially returns to shape after deformation.

A hydraulic system includes a first supply line connecting a boom control valve and a bottom side of a boom cylinder, a second supply line connecting the boom control valve and a rod side of the boom cylinder, a leveling switch valve having: a first operating position allowing a leveling operation of a working tool; and a first stopping position allowing the leveling operation to stop, a ride controller including: a ride-control switch valve connected to a branched fluid line branched from the first supply line; and an accumulator configured to perform an anti-vibrating operation for suppressing a pressure fluctuation of the boom cylinder, and a drain fluid line to discharge operation fluid in a downstream section extending from the leveling switch valve to the rod side of the boom cylinder in the second supply line when the leveling switch valve is switched to the first stopping position.

A working control device comprises an operation lever for making a boom cylinder (36), an arm cylinder (37) and others work to drive a shovel apparatus (30), and a delivered oil amount control device (a controller (150)). A working oil supply source includes a first electric motor (M1) and a first hydraulic pump (P1). When the operation lever is subjected to a single operation, a number of the motor revolution based on the lever operation is set to control the first electric motor. When the number of motor revolution is less than a necessary minimum number of revolutions, the necessary minimum number is set to control the first electric motor (M1). When the operation lever is subjected to a composite operation, a total number of motor revolutions based on the lever operations is set. When the total number is less than a necessary minimum number of revolutions, the necessary minimum number is set to control the first electric motor (M1).

The disclosed embodiments relates an arrangement for tilting or turning a tool, the arrangement including at least one actuator for tilting and turning the tool, the actuator including at least a frame part adapted to be closed by a cover, the frame part and the cover enclosing a chamber portion (8) where a blade part having one or more blade gaskets is provided to divide the chamber portion into separate chamber spaces, the blade part being connected, at its first end, to a shaft, the second end of the blade part being adapted move reciprocally in the chamber portion, rotating the shaft at the same time. The joint between the frame part and the cover is sealed by a gasket contacting the blade gaskets.

The object of the present invention resides in provision of a construction machine in which a hydraulic cylinder can be driven in a high efficiency by an accumulator. To this end, the construction machine including: a hydraulic cylinder; a first accumulator that accumulates return fluid from the hydraulic cylinder with a first set pressure; a tank that stores hydraulic fluid therein; a first hydraulic pump that delivers the hydraulic fluid sucked from the tank; a hydraulic actuator that is driven by the first hydraulic pump; and a second accumulator that accumulates return fluid from the hydraulic actuator with a second set pressure, includes a first control valve placed in a first hydraulic line that connects the first accumulator and the hydraulic cylinder to each other, and a second control valve placed in a second hydraulic line that connects the second accumulator and the hydraulic cylinder to each other. The second set pressure is set to a value higher than that of the first set pressure.

The present disclosure provides systems and methods for power machines, including a mini-loader that includes a frame, an operator station positioned toward a rear end of the frame and configured to be used by an operator who is behind or on the rear end of the frame, and a power source positioned toward a front end of the frame.

A working tool mounting mechanism for a tractor, includes: an extensible cylinder that is disposed on a tip of a boom of a front loader of the tractor, and comprises a cylinder body and a rod slidable with respect to the cylinder body; engaging parts that are respectively disposed on the cylinder body and the rod, and are each movable between an engagement position and a release position with extension and contraction of the extensible cylinder, the engaging parts each engaging with a working tool detachably attached to the boom at the engagement position, and not engaging with the working tool at the release position; a cover that covers the extensible cylinder from one direction; and a frame that is fixed to the cover and restricts at least one of: movement of the cylinder body and the rod in an extensible direction exceeding a predetermined position with the extension and contraction of the extensible cylinder, and rotation of the extensible cylinder around an axial direction.