Abstract: Provided is an electrically-driven flow rate control valve capable of controlling a flow rate of fluid while application of a high pressure of the fluid to a sub valve body connected to an electric motor is suppressed. A flow rate control valve includes a casing, an elevation drive device, and a main valve body. When the sub valve body moves upward by the elevation drive device, oil in a back pressure chamber is discharged. Moreover, the oil in a first oil chamber flows into the back pressure chamber while the flow rate of the oil is regulated. A balance among pressures in the back pressure chamber, the first oil chamber, and the second oil chamber changes, and the main valve body opens. When the main valve body is closed, a direct application of the pressure of the back pressure chamber to the sub valve body is blocked.

Abstract: Provided is an electrically-driven flow rate control valve capable of controlling a flow rate of a fluid flowing between two inlet/outlet ports, restraining a high pressure of the fluid from being applied to a sub valve body connected to an electric motor. The flow rate control valve has a casing, a raising/lowering drive device, a supply-switching valve, a main valve body, a valve-closing spring. When the electric motor of the raising/lowering drive device moves the sub valve body upward, oil of a back pressure chamber is discharged from a discharge oil passage through a sub valve body communication port and a sub valve body oil passage to open the main valve body. When the main valve body is closed, a pressure of the back pressure chamber is inhibited from being directly applied to a lower end face of the sub valve body.

Abstract: The energy recovery system includes an inertial fluid container, a low pressure container, a high pressure container, a low pressure valve, and a high pressure valve, a valve flow conduit, and a valve controller. The valve controller switches, in response to a decrease in volume of the fluid chamber, the inertial fluid container between communicating with the low pressure container and the high pressure container, thereby generating inertial forces of the working fluid flowing toward the low pressure container in the inertial fluid container, and causing the working fluid to flow into the high pressure container by the inertial forces. The valve controller sets a switching frequency for the valves to a frequency close to an Nth-order (where N is a natural number) anti-resonance frequency of a flow conduit for the working fluid.

Abstract: A hydraulic driving apparatus that drives a plurality of driving subjects and regenerates energy thereof. This hydraulic driving apparatus includes: a first pump motor; a second pump motor that is switchable between a state of moving a first driving subject by hydraulic oil discharged from the first pump motor and a state of being operated as a pump by means of energy of the first driving subject; a first pump motor line that couples the first and second pump motors with each other; a first accumulator connected to the first pump motor line; a regeneration subject hydraulic actuator that moves a second driving subject; a second accumulator that receives hydraulic oil from the regeneration subject hydraulic actuator; a second pump motor line that couples the second accumulator with the first pump motor; and a pressure release changeover valve that opens/closes the second pump motor line.

Abstract: Provided are an energy regeneration device which can regenerate energy of a working fluid discharged from an actuator while controlling a flow rate of the working fluid, and a work machine including the foregoing device. The regeneration device (100) includes a boom cylinder (20), an inertial fluid container (102), an oil tank (110), an accumulator (105), a low-pressure-side opening/closing device (103), and a high-pressure-side opening/closing device (104). A calculation unit (151) calculates a duty ratio for opening/closing the low-pressure-side opening/closing device (103) and the high-pressure-side opening/closing device (104) in accordance with a desired flow rate of a working fluid discharged from the boom cylinder (20).

Abstract: A hydraulic rotary machine configured to reduce sliding resistance of a reciprocating piston and to suppress a reduction in volumetric efficiency corresponding to an amount of leakage of hydraulic oil. A piston pump includes a rotor shaft, a cylinder block, a piston head, a piston rod, a retainer, a swash plate, and a tilt regulation mechanism. When the tilt regulation mechanism rocks the swash plate, the amount of discharge from the piston pump is variably changed. The retainer which rotates with both the piston head and the piston rod is supported by a retainer bush provided to the rotor shaft. The retainer sphere section of the retainer and the retainer bush sphere section of the retainer bush have spherical shapes having the same curvature. During the regulation of tilt, the retainer rocks while the retainer bush sphere section is in sliding contact with the retainer bush.

Abstract: A liquid pressure rotary machine in which a rotation delay of a retainer with respect to a cylinder block is reduced and contact of pistons placed between the retainer and the cylinder block with peripheral members is suppressed is provided. A piston pump includes a rotation shaft, a cylinder block, piston heads, piston rods, a retainer, a swash plate, and a tilt adjustment mechanism. When the tilt adjustment mechanism swings the swash plate, a discharge amount of the piston pump becomes variable. The retainer to be rotated together with the piston heads and the piston rods is supported by a retainer bushing provided in the rotation shaft. By engaging ball pins of the retainer bushing with spherical surface pin grooves of the retainer, the retainer and the retainer bushing are integrally rotatable about the center axis of the rotation shaft and the retainer is swung about the spherical surface center.

Abstract: Provided is an electrically-driven flow rate control valve capable of controlling a flow rate of a fluid flowing between two inlet/outlet ports, restraining a high pressure of the fluid from being applied to a sub valve body connected to an electric motor. The flow rate control valve has a casing, a raising/lowering drive device, a supply-switching valve, a main valve body, a valve-closing spring. When the electric motor of the raising/lowering drive device moves the sub valve body upward, oil of a back pressure chamber is discharged from a discharge oil passage through a sub valve body communication port and a sub valve body oil passage to open the main valve body. When the main valve body is closed, a pressure of the back pressure chamber is inhibited from being directly applied to a lower end face of the sub valve body.

Abstract: Provided is an electrically-driven flow rate control valve capable of controlling a flow rate of fluid while application of a high pressure of the fluid to a sub valve body connected to an electric motor is suppressed. A flow rate control valve includes a casing, an elevation drive device, and a main valve body. When the sub valve body moves upward by the elevation drive device, oil in a back pressure chamber is discharged. Moreover, the oil in a first oil chamber flows into the back pressure chamber while the flow rate of the oil is regulated. A balance among pressures in the back pressure chamber, the first oil chamber, and the second oil chamber changes, and the main valve body opens. When the main valve body is closed, a direct application of the pressure of the back pressure chamber to the sub valve body is blocked.

Abstract: The energy recovery system includes an inertial fluid container, a low pressure container, a high pressure container, a low pressure valve, and a high pressure valve, a valve flow conduit, and a valve controller. The valve controller switches, in response to a decrease in volume of the fluid chamber, the inertial fluid container between communicating with the low pressure container and the high pressure container, thereby generating inertial forces of the working fluid flowing toward the low pressure container in the inertial fluid container, and causing the working fluid to flow into the high pressure container by the inertial forces. The valve controller sets a switching frequency for the valves to a frequency close to an Nth-order (where N is a natural number) anti-resonance frequency of a flow conduit for the working fluid.

Abstract: An energy regeneration device capable of controlling flow of a working fluid discharged from an actuator while regenerating energy from the working fluid, and a work machine including the foregoing device, include a boom cylinder, an inertial fluid container, an oil tank, an accumulator, a low-pressure-side opening/closing device, and a high-pressure-side opening/closing device. A calculation unit calculates a duty ratio for opening/closing the low-pressure-side opening/closing device and the high-pressure-side opening/closing device in accordance with a desired flow rate of a hydraulic fluid discharged from the boom cylinder. A regeneration control unit selects alternately the low-pressure-side opening/closing device and the high-pressure-side opening/closing device as a destination with which the inertial fluid container communicates in accordance with the calculated duty ratio, and supplies the discharged hydraulic fluid to an accumulator.

Abstract: Provided is a hydraulic drive device that is provided in a work device and with which it is possible to obtain a high energy-saving effect with a low-cost configuration while being equipped with a plurality of hydraulic actuators. The hydraulic drive device is provided with: first and second actuator groups; closed circuits connected to hydraulic actuators included in the first actuator group; a pump section including closed circuit pumps; open circuits which include a plurality of variable throttle valves for changing the flow rate of working fluid supplied from a hydraulic pump included in the pump section to a hydraulic actuator; and circuit switching sections having a first state in which the closed circuits are opened and the opened circuits are blocked, and a second state in which the closed circuits are blocked and the open circuits are opened.

Abstract: An energy regeneration device which can regenerate energy of a working fluid discharged from an actuator while controlling a flow rate of the working fluid, and a work machine including the device. The regeneration device includes a boom cylinder, an inertial fluid container, an oil tank, an accumulator, a low-pressure-side opening/closing device, and a high-pressure-side opening/closing device. A calculation unit calculates an opening area of each of the low-pressure-side opening/closing device and the high-pressure-side opening/closing device in accordance with a desired flow rate of a hydraulic fluid discharged from the boom cylinder.

Abstract: A hydraulic driving apparatus that drives a plurality of driving subjects and regenerates energy thereof. This hydraulic driving apparatus includes: a first pump motor; a second pump motor that is switchable between a state of moving a first driving subject by hydraulic oil discharged from the first pump motor and a state of being operated as a pump by means of energy of the first driving subject; a first pump motor line that couples the first and second pump motors with each other; a first accumulator connected to the first pump motor line; a regeneration subject hydraulic actuator that moves a second driving subject; a second accumulator that receives hydraulic oil from the regeneration subject hydraulic actuator; a second pump motor line that couples the second accumulator with the first pump motor; and a pressure release changeover valve that opens/closes the second pump motor line.

Abstract: Provided is a hydraulic drive device that is provided in a work device and with which it is possible to obtain a high energy-saving effect with a low-cost configuration while being equipped with a plurality of hydraulic actuators. The hydraulic drive device is provided with: first and second actuator groups; closed circuits connected to hydraulic actuators included in the first actuator group; a pump section including closed circuit pumps; open circuits which include a plurality of variable throttle valves for changing the flow rate of working fluid supplied from a hydraulic pump included in the pump section to a hydraulic actuator; and circuit switching sections having a first state in which the closed circuits are opened and the opened circuits are blocked, and a second state in which the closed circuits are blocked and the open circuits are opened.

Abstract: Provided is a hydraulic shovel capable of moving a boom, an arm, and a bucket at respective adequate speeds even during complex operations thereof, without a significant pressure loss. This hydraulic shovel includes: a first pump (31) connected to a boom actuator (24) and a bucket actuator (28); a second pump (32) connected to an arm actuator (26) and the boom actuator (24); a third pump (33) connect to the arm actuator (26); a boom control valve (54) interposed between the first pump (31) and the boom actuator (24); an arm control valve (56) interposed between the second pump (32) and the arm actuator (26); a bucket control valve (58) interposed between the first pump (31) and the bucket actuator (28); a boom merging valve (55) for speed increase interposed between the second pump (32) and the boom actuator (24); and an arm merging valve (57) for speed increase interposed between the third pump (33) and the arm actuator (26).

Abstract: A reflector array optical device has a plurality of dihedral corner reflector array optical elements which are disposed side by side on the same plane. Each of the dihedral corner reflector array optical elements has a substrate and a plurality of dihedral corner reflectors which each have at least two orthogonal side faces perpendicular to the principal surface of the substrate and orthogonal to each other, and which are formed on the substrate so that the orientations of the interior angles of the orthogonal side faces are aligned with each other.

Abstract: Provided is a hydraulic driving apparatus for a working machine, preventing an excessive decrease in pressure on a meter-in side and moving a load at a stable speed in a lowering direction. The apparatus comprises: a hydraulic pump; a hydraulic actuator; a manipulation device; a working hydraulic circuit including a meter-in flow passage and a meter-out flow passage; a control valve for changing a state of supply of hydraulic fluid to drive the hydraulic actuator at a speed designated by the manipulation device; a meter-in flow adjuster and a meter-out flow adjuster adapted to adjust a meter-in flow rate and meter-in flow rate respectively to respective value corresponding to the speed designated by the manipulation device; and a relief valve. The meter-in and meter-out flow adjusters have respective flow adjustment characteristics such that the meter-in flow rate is greater than the meter-out flow rate.

Abstract: Provided is a hydraulic shovel capable of moving a boom, an arm, and a bucket at respective adequate speeds even during complex operations thereof, without a significant pressure loss. This hydraulic shovel includes: a first pump (31) connected to a boom actuator (24) and a bucket actuator (28); a second pump (32) connected to an arm actuator (26) and the boom actuator (24); a third pump (33) connect to the arm actuator (26); a boom control valve (54) interposed between the first pump (31) and the boom actuator (24); an arm control valve (56) interposed between the second pump (32) and the arm actuator (26); a bucket control valve (58) interposed between the first pump (31) and the bucket actuator (28); a boom merging valve (55) for speed increase interposed between the second pump (32) and the boom actuator (24); and an arm merging valve (57) for speed increase interposed between the third pump (33) and the arm actuator (26).

Abstract: Provided is an apparatus to lower a load, comprising a hydraulic pump, a hydraulic actuator having first and second ports, a manipulation device, a hydraulic circuit including meter-in and meter-out flow passages for the first and second ports respectively and a regeneration flow passage with a check valve, a control valve, a meter-out flow controller adjusting a meter-out flow rate according to the manipulation device, a back pressure valve, and a non-regeneration operation relief valve whose set pressure is not less than a sum of a minimum set pressure of the back pressure valve, an inlet-outlet pressure difference of the meter-out flow controller when the meter-out flow rate is maximum and a discharge flow rate of the hydraulic pump is maximum, and an actuator pressure difference for driving the hydraulic actuator with no load, and not less than a maximum set pressure of the back pressure valve.