Abstract: A hydraulic control device includes: a recovery oil passage; a regenerative motor that rotates an output shaft of an engine in response to a supply of the hydraulic fluid and is driven to rotate by rotation of the output shaft of the engine; a regenerative oil passage for guiding return oil from a boom cylinder to the regenerative motor without passing the return oil through the recovery oil passage; a coupling oil passage that couples the recovery oil passage and the regenerative oil passage to each other; and a regeneration-side check valve that is provided on the coupling oil passage, and allows the hydraulic fluid to flow from the recovery oil passage toward the regenerative motor, and moreover restricts the hydraulic fluid from flowing from the regenerative motor toward the recovery oil passage.

Abstract: A hydraulic control device includes: a recovery oil passage; a regenerative motor that rotates an output shaft of an engine in response to a supply of the hydraulic fluid and is driven to rotate by rotation of the output shaft of the engine; a regenerative oil passage for guiding return oil from a boom cylinder to the regenerative motor without passing the return oil through the recovery oil passage; a coupling oil passage that couples the recovery oil passage and the regenerative oil passage to each other; and a regeneration-side check valve that is provided on the coupling oil passage, and allows the hydraulic fluid to flow from the recovery oil passage toward the regenerative motor, and moreover restricts the hydraulic fluid from flowing from the regenerative motor toward the recovery oil passage.

Abstract: A controller includes a storage unit that stores a map in which an operation amount and an upper limit value of suction torque of a hydraulic pump are associated with each other, for each operation content identified by a cylinder that is an operation object out of the cylinders, and by a direction of operation performed on this cylinder; an operation torque determination unit that determines the upper limit value of suction torque for each cylinder by using the map stored in the storage unit when an actuation command relating to at least one cylinder is input by an operation lever; a high-level selection unit that selects the maximum upper limit value of suction torque out of the upper limit values of suction torque determined by the operation torque determination unit; and a regulator that regulates a displacement of the hydraulic pump so as to obtain torque equal to or lower than the suction torque selected by the high-level selection unit.

Abstract: A controller includes: a storage unit that stores a map in which an operation amount and an upper limit value of suction horsepower of a hydraulic pump are associated with each other, for each operation content identified by a cylinder that is an operation object out of the cylinders, and by a direction of operation performed on this cylinder; an operation horsepower determination unit that determines the upper limit value of suction horsepower for each cylinder by using the map stored in the storage unit when an actuation command relating to at least one cylinder is input by an operation lever; a high-level selection unit that selects the maximum upper limit value of suction horsepower out of the upper limit values of suction horsepower determined by the operation horsepower determination unit; and a regulator that regulates a displacement of the hydraulic pump so as to obtain horsepower equal to or lower than the suction horsepower selected by the high-level selection unit.

Abstract: In a hydraulic controller for construction machine according to the present invention, wherein there are provided regulators for each of a first and a second capacity variable hydraulic pump, each of the regulators being controlled, detecting the discharge pressure of each pump, in such a manner that one of the pumps absorbs a part of torque while the other thereof absorbs the remaining torque, and wherein a boom raising operation causes pressure oil from the pumps to be joined together and then supplied to a boom cylinder, while also a rotating operation causes pressure oil from the second pump to be supplied to a rotating motor, is provided a flow rate distribution controller adapted to control the regulators in such a manner that a difference in flow rate is provided between the pumps so that the first pump shows a higher flow rate at the start of a combined operation of raising and rotating, and that, on a steady rotating state which results in an increase in the discharge pressure difference between the

Abstract: In a hydraulic controller for construction machine according to the present invention, wherein there are provided regulators for each of a first and a second capacity variable hydraulic pump, each of the regulators being controlled, detecting the discharge pressure of each pump, in such a manner that one of the pumps absorbs a part of torque while the other thereof absorbs the remaining torque, and wherein a boom raising operation causes pressure oil from the pumps to be joined together and then supplied to a boom cylinder, while also a rotating operation causes pressure oil from the second pump to be supplied to a rotating motor, is provided a flow rate distribution controller adapted to control the regulators in such a manner that a difference in flow rate is provided between the pumps so that the first pump shows a higher flow rate at the start of a combined operation of raising and rotating, and that, on a steady rotating state which results in an increase in the discharge pressure difference between the

Abstract: A method for obtaining an optically active .alpha.-phenylglycine benzenesulfonate by optical resolutions which comprises dissolving DL-.alpha.-phenylglycine benzenesulfonate in an aqueous solution of benzenesulfonic acid, cooling the resulting solution to a temperature sufficient to render the solution supersaturated, selectively crystallizing either optically active D- or L-.alpha.-phenylglycine benzenesulfonate in the presence of a seed of either D- or L-.alpha.-phenylglycine benzenesulfonate corresponding to the optically active .alpha.-phenylglycine benzenesulfonate to be crystallized out, and separating the resulting crystals from the liquid phase is disclosed.