An impact hammer for breaking a working surface, the hammer including a drive mechanism and a housing with an inner containment surface and a reciprocating hammer weight. A reciprocation cycle of the hammer weight includes an upstroke and a down-stroke, the hammer weight respectively moving upwards and downwards. On the down-stroke the hammer weight impacts a striker pin with a driven end and a working surface impact end. A vacuum chamber in the housing is formed by the containment surface, upper vacuum sealing coupled to the hammer weight and lower vacuum sealing. The hammer weight is driven toward the striker pin by the pressure differential between atmosphere and the vacuum chamber formed on the upstroke. A down-stroke vent permits fluid egress from the vacuum chamber on the down-stroke.

A hose support structure includes a first round bar and a second round bar provided on a mounting surface of a first plate and extending in a first direction. A first restraint and a second restraint face the mounting surface in a second direction and are provided between the first round bar and the second round bar in a third direction. The first restraint extends from a first proximal end toward a first distal end in a fourth direction, and the second restraint extends in a fifth direction opposite to the fourth direction from a second proximal end connected to the first proximal end. A third restraint is provided opposite to the second restraint with respect to the first restraint in the first direction. At least a part of the second restraint is separated from the mounting surface by a second distance shorter than the first distance in the second direction.

A work vehicle includes computing system is configured to receive a first and seconds inputs associated with controlling an operation of first and second hydraulic loads. Furthermore, the computing system is configured to control the operation of the first or second flow control valve corresponding to the one of the first or second hydraulic loads associated with the greater hydraulic fluid pressure based on the corresponding received first or second input. Additionally, the computing system is configured to determine the first or second pressure of the hydraulic fluid being supplied to another of the first or second hydraulic loads. Moreover, the computing system is configured to control the first or second flow control valve corresponding to the other of the first or second hydraulic loads based on the corresponding received first or second input and the determined first or second pressure.

Provided is a hydraulic piping clamp device for a construction machine, with which it is possible to easily assemble a plurality of clamp members used to fasten hydraulic piping. A fastener (5) includes a bracket (6) and a plurality of clamp members (7). Hydraulic hoses (4) are respectively held by the plurality of clamp members (7). Each clamp member (7) has a holding portion (71) for holding a hydraulic hose and an insertion hole into which a guide bar (65) can be inserted. The clamp members (7) are mounted on the bracket (6) by inserting the guide bar (65) into the insertion hole in the clamp members (7). When two adjacent clamp members move away from one another, a first engaging portion (73) of one clamp member engages with a second engaging portion (75) of the other clamp member.

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.

Both a control for limiting operation of a machine body and a control for raising engine speed are achieved when an obstacle is detected. To this end, a machine controller performs operation limiting control by conducting a control for reducing the speed of the engine when the machine body does not require engine speed increase control and an obstacle is sensed by obstacle sensors, and the machine controller performs supply flow rate reduction control for reducing the flow rates of the hydraulic fluid supplied to hydraulic actuators from a hydraulic pump when the machine body requires the engine speed increase control and an obstacle is sensed by the obstacle sensors.

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.

Provided is a work vehicle capable of reducing the fuel consumption while maintaining the working efficiency. A wheel loader 1 comprising a vehicle body controller 5, 5A for controlling an engine 41, wherein the vehicle body controller 5, 5A limits an upper limit rotational speed of the engine 41 based on an accelerator pedal step-on amount α, a brake pedal step-on amount β, a torque converter speed ratio e which is a ratio of a rotational speed of a torque converter 42, a discharge pressure P1 of a loading hydraulic pump 44, and a stroke amount S1 of lift arm cylinders 22 or a stroke amount S2 of a bucket cylinder 24.

The present invention provides a construction machine equipped with a pressure accumulation device that accumulates return oil from an actuator, and that can implement both improvement in fuel efficiency with enhancement in workability. To achieve the foregoing, a controller sets an actuator upper limit output power that is an upper limit for an output power of the actuator according to a work mode selected by a work mode selection device, and controls a first control valve and a second control valve such that a sum of an output power of a hydraulic pump and an output power of the pressure accumulation device does not exceed the actuator upper limit output power.

A hydraulic excavator includes a traveling body, a slewing body, a working front having a boom, an arm, and a bucket, an operation amount detector, a posture detector, a load detector, a drive controller, and a drive unit. The drive controller calculates a target operation speed of the actuator based on the operation amount, the posture of the working front, and the target surface distance so that the bucket excavates along the construction target surface, and determines soil hardness of a place to be excavated based on a result detected by the load detector, corrects the target operation speed based on the soil hardness, and generates a motion command value. The drive controller determines a target jack-up speed when the hydraulic excavator jacks up based on the target surface distance, and corrects the target operation speed based on the determined target jack-up speed.